Question

помогите решить уравнение 12х+18*(60-х)=240

Answer 1

4x + 6*(60-x) = 80
4x + 6*60 - 6x = 80
6*60 - 80 = 6x - 4x
2x = 6*60 - 80
x = 6*30 - 40
x = 140

Answer 2

12х+18*(60-х)=240
12х+1080-18х=240
-6х=240-1080
-6х=-840
х=-840/(-6)
х=140