解方程组﹛﹙x+2﹚²-﹙y-3﹚²=﹙x+y﹚﹙x-y﹚ x-3y=2
问题描述:
解方程组﹛﹙x+2﹚²-﹙y-3﹚²=﹙x+y﹚﹙x-y﹚ x-3y=2
答
(x+2)² -(y-3)²=(x+y)(x-y)
整理得
x^2+4x+4-y^2+6y-9=x^2-y^2
即4x+6y-5=0 (1)
x-3y=2 (2)
(2)×2+(1)得
6x=9
x=3/2,y=-1/6