Question

计算2x+4/x^2+6x+9除以(x+2)乘以x^2+x-6/8-4x的值

Answer 1

(x-1)(3x+1)-(x+1)^2

=3x^2-2x-1-x^2-2x-1

=2x^2-4x-2

=2(x^2-2x)-2

=2×1-2

=0

x轴上y=0

y= -2（x-3）（x+1）=0

x=3,x=-1

所以是(3,0)和(-1,0)