đề thi học kì 2 toán 8

ĐỀ KIỂM TRA HK 2
Môn Toán 8
Thời gian: 90 phút
Điểm
Lời phê của thầy (cô)

Bài 1:Giải các phương trình sau:(3 điểm)
a) 5
2𝑥−4=3
𝑥−2

b)
4𝑥
5
3𝑥−2
10=1
𝑥
2

c)
5𝑥+1
2−3𝑥=0
Bài 2:Giải các bất phương trình sau:(2 điểm)
a)
2𝑥−3
2𝑥+3−4𝑥
4𝑥
2−13
b)
5𝑥−2
3
3
4
2𝑥−7
12

Bài 3:(0,5 điểm) Tính chiều rộng của khúc sông AB trong hình vẽ sau:
A
34,2m B`
B 79,6m O 18,6m
A`
Bài 4: (2 điểm)
Một ô tô đi từ A đến B với vận tốc 40 km/h. Lúc về xe đi với vận tốc 60km/h nên thời gian về ít hơn thời gian đi 30 phút. Tính quãng đường AB?
Bài 5: (2,5 điểm)
Cho tam giác ABC vuông tại A có đường cao AH.
a) ∆HBA ~∆ABC từ đó suy ra AB2=BH.BC
b) Chứng minh: AH2=HB.HC
c) Tia phân giác của góc
𝑩 cắt AH tại E, cắt AC tại D. Tính độ dài ED. Biết AB=3cm, AC=4cm.
Bài làm
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