3.61-3.42a+0.81a²
Пошаговое объяснение:
(1.9-0.9a)²=(1.9-0.9a)(1.9-0.9a)=1.9²-1.9*0.9a-1.9*0.9a+(0.9a)²=3.61-3.42a+0.81a²
3.61-3.42a+0.81a²
Пошаговое объяснение:
(1.9-0.9a)²=(1.9-0.9a)(1.9-0.9a)=1.9²-1.9*0.9a-1.9*0.9a+(0.9a)²=3.61-3.42a+0.81a²