已知x^2-8x+y^2+6y+25=0,求（x+y- 4xy/x+y）（x-y+ 4xy/x-y）的值_数学解答

已知x^2-8x+y^2+6y+25=0,求（x+y- 4xy/x+y）（x-y+ 4xy/x-y）的值

人气：488 ℃　时间：2020-04-08 13:25:13

解答

x²-8x+y²+6y+25=0
(x-4)²+(y+3)²=0
x-4=0x=4
y+3=0 y=-3
(x+y-4xy)/(x+y)×(x-y+4xy)/(x-y)
=(4-3+48)/1×(4+3-48)/7
=-287