Question

what 18x+90=180 i have to solve like a equation

Answer 1

18x+90=180
       -90  -90     Subtract 90 from both sides
__________
18x=90
/18  /18     Divide 18 on both sides
__________
x=5

Answer 2

$18x+90=180 \\ 18x+90-90=180-90 \\ 18x=90 \\ 18x/18=90/18 \\ x=5$