Упростите: 1) 4a(a-2)-(a-4)^2; 2)2(b+1)^2-4b; 3) (a^2+4a)^2-a^2(a-2)(a+2)-4a^2(2a-1).

Question

Упростите: 1) 4a(a-2)-(a-4)^2;
2)2(b+1)^2-4b;
3) (a^2+4a)^2-a^2(a-2)(a+2)-4a^2(2a-1).

Answer 1

1)4a(a-2)-(a-4)²=4a²-8a-a²+8a-16=3a²-16
2)2(b+1)²-4b=2((b+1)²-2b)=2(b²+2b+1-2b)=2(b²+1)
3)(a²+4a)²-a²(a-2)(a+2)-4a²(2a-1)=a^4+8a³+16a²-a^4+4a²-8a³+4a²=24a²