Question

2x+4×(40-x)=100
Чему равен x ?

Answer 1

2Х+160-4Х=100
4Х-2Х=160-100
2Х=60
Х=30

Answer 2

2х+4(40-х)=100
2х+160-4х=100
160-100=-2х+4x
60=2x
x=60/2
x=30