How I write two subtraction equations to show how to find 15-7

Answer 1

maybe
15 - 7 = 15+3 - 7 - 3 = 18 - 10 = 8
or
15 -5 - 7+5 = 10 - 2 = 8

Answer 2

15 - (3 + 4) = 8.
(3*5) - 7 = 8.
15 - 3 - 4 = 8.