Question

Как найти (х-50)+(х+70)+(х+100)=870?

Answer 1

(x-50)+(x+70)+(x+100)=870
x-50+x+70+x+100=870
3x+120=870
3x=870-120
3x=750
x=750/3
x=250
ответ: 250

Answer 2

х-50+х+70+х+100=870
х+х+х=870+50-70-100
3х=750
х=750:3
х=250