Question

5x2+5x+6/x2(x2+x+3)

x2+5x+6除以x+2这个怎么解?
x2+5x+6
=x^2+(2x+3x)+2*3
=(x+2)(x+3)
就是不明白为什么得出这个结果来,

Answer 1

=x^2+(2x+3x)+2*3
= x^2+2x+3x+2*3
=x(x+2)+3(x+2)
=(x+2)(x+3)