1) 5/18 - 3 1/15 = -(3 1/15 - 5/18) = -(3 6/90 - 25/90) = -(2 96/90 - 25/90) = -2 71/90

2) -2 71/90 * 9 = -251/90 * 9 = -251/10 = -25,1

Ответ: -25,1