Question

What is (2n + 20) + 60 = 90?

Answer 1

(2n +20) +60 = 90
               -60    -60
2n+20= 30
    -20    -20
2n=10
divide by two on both sides
n=5

Answer 2

2n+20+60=90 2n+80 =90 2n+80 =90 80 -80 2n =10 2 2 n =5