Question

упростить выражения:
а) (3-5m)(3+5m)-10m(6+2m)
б) 2a(3a-5)-(a-3)²

Answer 1

1) 9-25m²-60m-20m²= -45m²-60m+9= -3(15m²+20m-3)
2) 6a²-10a-(a²-6a+9)=6a²-10a-a²+6a-9=5a²-4a-9