Thi thử vào lớp 10 của trường THCS Trường Sơn - sầm sơn năm 2011-2012

ĐỀ THI THỬ VÀO LỚP 10 THPT Năm học 2011– 2012- Môn thi: Toán
Thời gian làm bài: 120 phút
Nguyễn Văn Chương – bài thứ bảy - Đề thi thử củaTrường THCSTrường Sơn - Sầm Sơn
Điểm
Nhận xét của Thầy Giáo




ĐỀ BÀI: Câu1:(2Điểm ) 1) Cho biểu thức B =

1) Rút gọn biểu thức B
2) Tinh giá trị của biểu thức B khi : x = 5 + 2

Câu2: ( 2Điểm ) 1) Giải hệ phương trình :

2) Cho hai đường thẳng (d) : y = (m2 -3m).x+1 và ( d’): y = 4x – m .Tìm m để (d) // (d’)
Câu3: ( 2Điểm ) Cho phương trình ( ẩn x) : x2 +2(m+1).x + m2 -1 = 0 (1)
a) Giải phương trình (1) khi m = 1
b) Tìm giá trị của m để phương trình có hai nghiệm x1 và x2 thoả mãn :

Câu4: ( 3Điểm ) Cho đường tròn tâm ( O) ; dây AB không đi qua tâm . Trên cung nhỏ AB lấy điểm H ( H không trùng với A; B) .Kẻ dây HN vuông góc với AB tại M . Kẻ HK vuông góc với AN ( K
AN)
1) Chứng minh bốn điểm A; H; M; K thuộc một đường tròn
2 ) Chứng minh HN là tia phân giác của góc BHK
3) Khi H di chuyển trên cung nhỏ AB Gọi E là giao điểm của MK và BN xác định vị trí của điểm H để ( HK . AN + HE . NB) có giá trị nhỏ nhất
Câu5: ( 1Điểm ) Cho ba số dương : a; b; c Chứng minh rằng :

+
+

2

bài làm .........................................................................................................................................................................................................................................
............................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
.......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
..........................................................................................................................................................................................................................................
..........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
............................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
.....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
...........................................................................................................................................................................................................................................
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................