Question

数学题=y(y+3)-4(y+3)2=(y+3)(y-4y-12)

Answer 1

(y+3)^2/8-y=(y+3)/4-(y-1)/2

各项都乘以8,得

(y+3)^2-8y=2(y+3)-4(y-1)

y^2-2y+9=-2y+10

y^2=1

y1=-1 y2=1