2X^2+6=7X
2X^2-7x+6=0
(2x-3)(x-2)=0
x=1.5x=2
（2－X）^2+X^2=4
X^2-4x+4+X^2=4
2X^2-4x=0
2X(x-2)=0
x=0 x=2