Question

[Thị Mai Phương Trần]

tìm số nguyên x,biết:

A,-4/7=x/21

B.(x-3)/15=1/-5

C.(3x+8)/-12=-5/30

Answer 1

[☞Tᖇì ᑎGâᗰ ☜]

a,-4/7=x/21
-12/21 = x/21
x= -12 

b,(x-3)/15=1/-5
x - 3 = -1/5 * 15
x - 3 = -3
x = 0

c,.(3x+8)/-12=-5/30
=> 3x + 8 = 2
=> 3x=-6
=>x=-2