Question

tìm x thuộc Z biết :  

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

Answer 1

=> -12x+60+21x=5
=>9x -55=0
=>x=\(\frac{55}{9}\)

Answer 2

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

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

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

\(\Rightarrow9x+60=5\)

\(\Rightarrow9x=5-60\)

\(\Rightarrow9x=-55\)

\(\Rightarrow x=\frac{-55}{9}\)