a)-x+25=29
=>-x=4
=>x=4
b)8x = -16
=>x=-2
=>x=2
c)=>\(\orbr{\begin{cases}12+x=7\\12+x=-7\end{cases}}\Rightarrow\orbr{\begin{cases}x=-5\\x=-19\end{cases}}\)
-45.67-67.55=-6700
-x+25=11+18
-x+25=29
x=25-29
x=-4
b -11+8x=-27
-3x=-27
x=-27:-3
x=9
c 12+x=7
12+x=-7
x=19
x=5
23+(-14)-(-45)+(+21)-16
-40+(12-27)-(-39-42)
(-17+27).(-3+(-2)2
(-3)3-4.[20-3.9]