Question

3x=9o?
2x+10=70?
2x+80=3x?

Answer 1

-3x-2x= 80
-x=80 (-1)
x=80

Answer 2

3x = 90      x = 90/3      x = 30
2x + 10 = 70      2x = 70 - 10      2x=60    x=60/2  x=30
2x + 80 = 3x      2x - 3x = -80     -x = -80   .(-1)       x=80