Question

tìm x 

-12(x-5)+7(3-x)=5

giúp mình với khó quá

 

Answer 1

-12(x-5)+7(3-x)=5

-12x - (-60) + 21 - 7x = 5

- (12x+7x) + (60+21) = 5

-19x + 81 = 5

-19x = 5 - 81

-19x = -76

x = -76 : (-19)

x = 4

Answer 2

Ta có \(-12.\left(x-5\right)+7.\left(3-x\right)=5\)

\(\Rightarrow-12x+60+21-21x=5\)

\(\Rightarrow\left(-12x-21x\right)+\left(60+21\right)=5\)

\(\Rightarrow-33x+81=5\)

\(\Rightarrow-33x=-77\)

\(\Rightarrow x=\frac{7}{3}\)