1.ax²—16ay² 2.-2a³+16a²+40a 3.-2x³y³+4x²y² 4 .2a(x-2y)-3b(2y-x)-4c(x-2y) 5.(x+1)²-4x 6.（y-3)(y+5)+16 7.4（a-2b)²-9(2a+b)² 8.9（a+b)²+6(a+b)+1

1.ax²—16ay² 2.-2a³+16a²+40a 3.-2x³y³+4x²y² 4 .2a(x-2y)-3b(2y-x)-4c(x-2y) 5.(x+1)²-4x 6.（y-3)(y+5)+16 7.4（a-2b)²-9(2a+b)² 8.9（a+b)²+6(a+b)+1
1.ax²—16ay² 2.-2a³+16a²+40a 3.-2x³y³+4x²y² 4 .2a(x-2y)-3b(2y-x)-4c(x-2y) 5.(x+1)²-4x 6.（y-3)(y+5)+16 7.4（a-2b)²-9(2a+b)² 8.9（a+b)²+6(a+b)+1

1.ax²—16ay² 2.-2a³+16a²+40a 3.-2x³y³+4x²y² 4 .2a(x-2y)-3b(2y-x)-4c(x-2y) 5.(x+1)²-4x 6.（y-3)(y+5)+16 7.4（a-2b)²-9(2a+b)² 8.9（a+b)²+6(a+b)+1
1.ax²—16ay²
=a(x²-16y²)
=a(x+4y)(x-4y)

2. -2a³+16a²+40a
=-2a(a²-8a-20)
=-2a(a-10)(a+2)

3. -2x³y³+4x²y²
=-2x²y²(xy-2)

4 .2a(x-2y)-3b(2y-x)-4c(x-2y)
=2a(x-2y)+3b(x-2y)-4c(x-2y)
=(x-2y)(2a+3b-4c)

5.(x+1)²-4x
=x²+2x+1-4x
=x²-2x+1
=(x-1)²

6.（y-3)(y+5)+16
=y²+2y-15+16
=y²+2y+1
=(y+1)²

7.4（a-2b)²-9(2a+b)²
=[2(a-2b)+3(2a+b)][2(a-2b)-3(2a+b)]
=(8a-b)(-4a-7b)
=-(8a-b)(4a+7b)

8. 9（a+b)²+6(a+b)+1
=[3(a+b)+1]²
=(3a+3b+1)²