Решити премер х+21=42-3х

Question

Решити премер х+21=42-3х

Answer 1

Х+21=42-3х
х+3х=42-21
4х=21
х=21/4
х=5,25

Answer 2

X+21=42-3
x=39-21
x=18
18+21=42-3
39=39