Question

a+b=36;a = b:5;a=?,b=?

Answer 1

a+b=36
a=b:5 → b=5a

a+5a=36
6a=36
a=36:6
a=6
b=5•6=30

Answer 2

$a + b = 36 \\ a = b \div 5 \\ b = 5a \\ a + 5a = 36 \\ 6a = 36 \\ a = 36 \div 6 \\ a = 6 \\ b = 36 - 6 \\ b = 30$