a) 70-5(x-3)=45
5(x-3)=70-45
5(x-3)=25
x-3=25:5
x-3=5
x=5+3
x=8
vậy x=8
b)10+2x=45:43
10+2x=42
10+2x=16
2x=16-10
2x=6
x=6:2
x=3
vậy x=3
\(a.70-5.\left(x-3\right)=45\)
\(70-\left(x-3\right)=45:5\)
\(70-\left(x-3\right)=9\)
\(x-3=70-9\)
\(x-3=61\)
\(x=61+3\)
\(x=64\)
\(b.10+2.x=4^5:4^3\)
\(10+2.x=4^2=16\)
\(2.x=16-10\)
\(2.x=6\)
\(x=6:2\)
\(x=3\)
Học tốt !
70-5.(x-3)=45
5.(x-3)=70-45
5.(x-3)=25
x-3=25:5
x-3=5
x=5+3
x=8