Question

解方程组:(x+y)²-3（x+y)-10=0 x²-8xy+16y²=25

Answer 1

因式分解

(x+y)^2-3(x+y)-10=(x+y+2)(x+y-5)=0

(x^2-8xy+16y^2)=(x-4y)^2=25

如果x+y+2=0且x-4y=5,则x=-0.6,y=-1.4

如果x+y+2=0且x-4y=-5,则x=-2.6,y=0.6

如果x+y-5=0且x-4y=5,则x=5,y=0

如果x+y-5=0且x-4y=-5,则x=3,y=2