Bài 1 :
a) ${ (-19-x)+23=-20}$
`=>` ${ -x=-20-23+19}$
`=>` ${ -x=-24}$
`=>` ${ x=24}$
Vậy $ {x=24}$
b) ${(x-45):2=-17}$
`=>` ${ x-45= -17.2}$
`=>` ${ x-45=-34}$
`=>` ${ x = -34+45}$
`=>` ${ x= 11}$
Vậy $ {x=11}$
Bài 2 :
a) ${ |x+3|=15}$
`=>` \(\left[ \begin{array}{l}x+3=15\\x+3=-15\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=12\\x=-18\end{array} \right.\)
Vậy ${ x\in}$$\text{ {12;-18}}$
b) ${ |x-7|+13=25}$
`=>` ${ |x-7|= 25-13}$
`=>` ${ |x-7|= 12}$
`=>` \(\left[ \begin{array}{l}x-7=12\\x-7=-12\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=19\\x=-5\end{array} \right.\)
Vậy ${ x\in}$$\text{ {19;-5}}$
c) ${ |x-3|-16=-4}$
`=>` ${ |x-3|=-4+16}$
`=>` ${ |x-3| = 12}$
`=>` \(\left[ \begin{array}{l}x-3=12\\x-3=-12\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=15\\x=-9\end{array} \right.\)
Vậy ${ x\in}$$\text{ {15;-9}}$
d) ${ 26 - |x+9| =-13}$
`=>` ${ |x+9|= 26 +13}$
`=>` ${ |x+9|= 39}$
`=>` \(\left[ \begin{array}{l}x+9=39\\x+9=-39\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=30\\x=-48\end{array} \right.\)
Vậy ${ x\in}$$\text{ {-48;30}}$
c) ${ |x-3|-16=-5}$
`=>` ${ |x-3|=-5+16}$
`=>` ${ |x-3| = 11}$
`=>` \(\left[ \begin{array}{l}x-3=11\\x-3=-11\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=14\\x=-8\end{array} \right.\)
Vậy ${ x\in}$$\text{ {14;-8}}$
