1,
$x-45=48-68$
$⇒x-45=-20$
$⇒x=25$
Vậy $x=25$
2,
$35+5(6-x)=(-12)+112$
$⇒35+5(6-x)=100$
$⇒5(6-x)=65$
$⇒6-x=13$
$⇒x=-7$
Vậy $x=-7$
3,
$126=3(x-9)$
$⇒x-9=42$
$⇒x=51$
Vậy $x=51$
4,
$157-(x-124)=-483$
$⇒x-124=640$
$⇒x=764$
Vậy $x=764$
5,
$46-(3x-2)^2=(-38)+20$
$⇒46-(3x-2)^2=-18$
$⇒(3x-2)^2=64$
$+,3x-2=8$
$⇒3x=10$
$⇒x=\dfrac{10}{3}$
$+,3x-2=-8$
$⇒3x=-6$
$⇒x=-2$
Vậy `x∈{\frac{10}{3};-2}`
6,
$13-|x+6|=-7-10$
$⇒13-|x+6|=-17$
$⇒|x+6|=30$
$+,x+6=30$
$⇒x=24$
$+,x+6=-30$
$⇒x=-36$
Vậy `x∈{24;-36}`