12.5×（36－7.2）÷3.6
(12.5 x 36 - 12.5 x 7.2) ÷ 3.6
12.5 x 36 ÷ 3.6 - 12.5 x 7.2 ÷ 3.6
12.5 x 10 -12.5 x 2
12.5 x (10 - 2)
12.5 x 8
100