Я заменю m на x (m=x)

3.2x = 8/3

x = 8/3 * 10/32

x = 5/6

(25/40x - 8/40) * 30/40 = 15/40

3/8x - 3/20 = 15/40

15/40x - 6/40 = 15/40

15/40x = 15/40 + 6/40

X = 21/40 : 15/40

X = 1,4