Question

given;n+8(n+20)=110
1;n+8n+20=110
2;9n+20=110
3;9n=110-20
49n=90

Answer 1

n+8n+60=110
n+8n=110-60
9n=50
n=50/9

Answer 2

you forgot to multiply 20 by 8:
n+8(n+20)=110
must be
n+8n+160=110
but you're on the right track~ :)