(3/2)³-5*(3/2)²+7=
27/8-5*9/4+7=
27/8-45/4+7=
27/8-90/8+56/8=
-7/8
(3/2)³ - 5 · (3/2)² + 7 = 27/8 - 5 · 9/4 + 7 = 27/8 - 45/4 + 7 = -63/8 + 7 = - 7 7/8 + 7 = -7/8
Ответ. -7/8