(15х+18)+(22-12х)=100

Question

(15х+18)+(22-12х)=100

Answer 1

15x-12x=100-22-18
3x=60
x=60/3
x=20

Answer 2

1. Раскрой скобки 
15х+18+22-12х=100
2. 3х+40=100
3х=60
х=20