y=2(x+1)(x-5)怎么化为y=2x²-8x-10

问题描述:

y=2(x+1)(x-5)怎么化为y=2x²-8x-10

y=2(x+1)(x-5)
y=2(x²-5x+x-5)
y=2(x²-4x-5)
y=2x²-8x-10