× + 9х=8000 2•(100+×)=400

Question

× + 9х=8000 2•(100+×)=400

Answer 1

х+9х=8000

10х=8000

х=8000:10

х=800

2*(100+х)=400

200+2х=400

2х=400-200

2х=200

х=200:2

х=100