Question

Tim x

A, 3/8 = 6/ x

B, x/4 = 18/ x+1

C, 3/ x-5 = -4 / x + 2

Answer 1

\(\dfrac{3}{x-5}=\dfrac{-4}{x+2}\)=>3.(x+2)=(x-5).(-4)

=> 3.2+3.x=x.(-4)-(-4).5

=>6+3.x=x.(-4)-(-20)

=>3.x-x.(-4)=20-6

=>3.x-x.(-4)=14

=>x.(3+4)=14(vì 3-(-4)=3+4)

=>x.7=14

=>x=14:7

=>x=2

Answer 2

\(\dfrac{3}{8}=\dfrac{6}{x}\) =>3.x=6.8

3.x=48

x=48:3

x=16

Answer 3

mấy ý sau làm tương tự nhé

Answer 4

a) 3/8 = 6/x

=> 3.x = 8.6

=> 3.x = 48

=> x = 48:3

=> x = 19