阅读下列用配方法分解因式过程X^2+10X+9=X^2+2×5X+5^2-16=X^2+2×5X+5^2-4^2=（X+5)^2-4^2=(X+5+4)(X+5-4)=(X+9)(X+1)1.X^2-6x-162.Y^2-8Y-20

Question

阅读下列用配方法分解因式过程 X^2+10X+9=X^2+2×5X+5^2-16=X^2+2×5X+5^2-4^2=（X+5)^2-4^2=
(X+5+4)(X+5-4)=(X+9)(X+1) 1.X^2-6x-16 2.Y^2-8Y-20

Answer 1

1.X^2-6x-16
=x²-2×3x+3²-25
=x²-2×3x+3²-5²
=(x-3)²-5²
=(x-3+5)(x-3-5)
=(x+2)(x-8)
2.Y^2-8Y-20
=y²-2×4y+4²-36
=y²-2×4y+4²-6²
=(y-4)²-6²
=(y-4+6)(y-4-6)
=(y+2)(y-10)