Question

a-21=15;a+32=65;53+a=58

Answer 1

1. a=36
2. a=33
3. a=5

Answer 2

$a-21=15 \\ a=15+21 \\ a=36 \\ a+32=65 \\ a=65-32 \\ a=33 \\ 53+a=58 \\ a=58-53 \\ a=5$