\(\left(158-x\right):7=20\)
\(158-x=20\cdot7\)
\(158-x=140\)
\(x=158-140\)
\(x=18\)
\(231-\left(x-6\right)=\frac{1339}{13}\)
\(231-\left(x-6\right)=103\)
\(231-103=x-6\)
\(x-6=128\)
\(x=134\)
\(\frac{81+2x}{5}=25\)
\(\left(81+2x\right):5=25\)
\(81+2x=25\cdot5\)
\(81+2x=125\)
\(2x=125-81\)
\(2x=44\)
\(x=22\)
1.(158-x):7=20
158-x =20.7
158-x =140
x =158-140
x =18
2.231-(x-6)=1339/13
231-(x-6)=103
x-6=231-103
x-6=128
x =128+6
x =134
3.(81+2.x)/.5=25
81+2.x =25.5
81+2.x =125
2.x =125-81
2.x =44
x =44:2
x =22
k mik nha
1.(158-x):7=20
2.231-(x-6)=1339/13
3.(81+2.x)/5=25
1.(158-x):7=20
158-x =20.7
158-x =140
x =158-140
x =18
2.231-(x-6)=1339/13
231-(x-6)=103
x-6=231-103
x-6=128
x =128+6
x =134
3.(81+2.x)/.5=25
81+2.x =25.5
81+2.x =125
2.x =125-81
2.x =44
x =44:2
x =22
