1 )
-12( x - 5 ) + 7( 3 - x ) = 5
<=> -12x + 60 + 21 -7x = 5
<=> -12x -7x = 5 - 21 - 60
<=> -19x = -76
<=> x = \(\frac{-76}{-19}\)
<=> x = 4
\(1)\)
\(-12\left(x-5\right)+7\left(3-x\right)=5\)
\(\Rightarrow-12x--12.5+7.3-7x=5\)
\(\Rightarrow-12x-\left(-60\right)+21-7x=5\)
\(\Rightarrow-12x+60+21-7x=5\)
\(\Rightarrow-19x+81=5\)
\(\Rightarrow-19x=5-81\)
\(\Rightarrow-19x=-76\)
\(\Rightarrow x=-76:-19\)
\(\Rightarrow x=4\)
Vậy \(x=4\)
\(2)\)
Ta có :
\(\left|x\right|< 3\Rightarrow\left|x\right|\in\left\{0;1;2\right\}\)
Với \(\left|x\right|=0\Rightarrow x=0\)
Với \(\left|x\right|=1\Rightarrow\orbr{\begin{cases}x=1\\x=-1\end{cases}}\)
Với \(\left|x\right|=2\Rightarrow\orbr{\begin{cases}x=2\\x=-2\end{cases}}\)
Vậy \(x\in\left\{0;1;-1;2;-2\right\}\)
~ Ủng hộ nha
1 ) - 12 . ( x - 5 ) + 7 . ( 3 - x ) = 5
( - 12 ) . x + 12 . 5 + 7.3 - 7.x = 5
( - 12 ) . x + 60 + 21 - 7 . x = 5
( - 12 ) . x + 81 - 7 . x = 5
x . ( - 12 - 7 ) + 81 = 5
x . ( - 19 ) = 5 - 81
x . ( - 19 ) = - 76
x = ( - 76 ) : ( - 19 )
x = 4