X•4=36?7•x=21?x:5=3?20:x=4?

Question

X•4=36?7•x=21?x:5=3?20:x=4?

Answer 1

1)x=9
2)x=3
3)x=15
4)x=5

Answer 2

Х•4=36
Х=36:4
Х=9
7•х=21
Х=21:7
Х=3
Х:5=3
Х=5•3
Х=15
20:х=4
х=20:4
Х=5