x²+7x+10 x²-2x-8 y²-7y+12 x²+7x-18 四道因式分解

Question

①x²+7x+10
②x²-2x-8
③y²-7y+12
④ x²+7x-18

Answer 1

x²+7x+10
=x²+2x+5x+10
=x(x+2)+5(x+2)
=(x+2)(x+5)
x²-2x-8
=(x+2)(x-4)
y²-7y+12
=(x-3)(x-4)
x²+7x-18
=(x+2)(x-9)

Answer 2

x²+7x+10=(x+5)(x+2)
x²-2x-8 =(x-4)(x+2)
y²-7y+12 =(x-3)(x-4)
x²+7x-18 =(x+9)(x-2)

Answer 3

x²+7x+10=(x+2)(x+5)
x²-2x-8=(x-4)(x+2)
y²-7y+12 =(y-3)(y-4)
x²+7x-18 =(x+9)(x-2)

希望对你有帮助：）