Question

4*(3400-х) +800=8000 найти х?

Answer 1

4*(3400-х)+800=8000
4*(3400-х)=8000-800
3400-х=7200:4
-х=1800-3400
-х=-1600
х=1600

Answer 2

13600-4x+800=8000
-4х=8000-800-13600
-4х=-6400
4х=6400
х=6400:4
х=1600