Question

Tim x biết : -12(x-5)+7(3-x)=5

Answer 1

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

\(-12\times x+12\times5+7\times3-7\times x=5\)

\(x\times\left(-12-7\right)+\left(60+21\right)=5\)

\(x\times\left(-19\right)+81=5\)

\(x\times\left(-19\right)=5-81\)

\(x\times\left(-19\right)=-76\)

\(x=\frac{-76}{-19}\)

\(x=4\)

Chúc bạn học tốt

Answer 2

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

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

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

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

x . ( - 12 - 7 ) - [( - 60 ) - 21 )] = 5

-19x - ( - 81 ) = 5

-19x = 5 + ( -81 )

-19x = -76

      x = (-76) : ( -19)

      x = 4

Vậy x = 4

Answer 3

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

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

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

\(-19x=-76\)

\(x=4\)