a) -x - 84=-16-213
-x-84=-229
-84+229=x
145 =x
b) /x+2/= 316
suy ra x+2=316 hoac x+2=-316
* x+2 = 316
x = 314
* x+2 =-316
x = -318
vay x=314 hoac x=-318
c) /x+7/=15
suy ra x+7=15 hoac x+7=-15
x+7=15
x = 8
x+7= -15
x = -22
vay x= 8 hoac x=-22
d) 19-4=/x-1/
15=/x-1/
suy ra x-1=15 hoac x-1=-15
x-1=15
x = 16
x-1=-15
x= -14
vay x=16 hoac x=-14
\(-\left(x+84\right)+213=-16\)
\(=>-x-84+213=-16\)
\(=>-x=-16+84-213=-145\)
\(=>x=145\)
\(\left|x+2\right|=341+\left(-25\right)\)
\(=>\left|x+2\right|=341-25=316\)
\(=>\orbr{\begin{cases}x+2=316\\x+2=-316\end{cases}}\)
\(=>\orbr{\begin{cases}x=314\\x=-318\end{cases}}\)
\(\left|x+7\right|=\left|-15\right|\)
\(=>\left|x+7\right|=15\)
\(=>\orbr{\begin{cases}x=15-7\\x=-15-7\end{cases}}\)
\(=>\orbr{\begin{cases}x=8\\x=-22\end{cases}}\)
\(19-\left|x-1\right|=4\)
\(=>\left|x-1\right|=19-4=15\)
\(=>\orbr{\begin{cases}x-1=15\\x-1=-15\end{cases}}\)
\(=>\orbr{\begin{cases}x=16\\x=-14\end{cases}}\)