ax的平方+2x(b-2x)+b+2=0
ax²+2bx-4x²+b+2=0
ax²-4x²+2bx+b+2=0
(a-4)x²+2bx+b+2=0
△=4b²-4(a-4)(b+2)
=4b²-4(ab-4b+2a-8)
=4(b²-ab+4b-2a+8)
x=[-b±√(b²-ab+4b-2a+8)]/(a-4)
ax的平方+2x(b-2x)+b+2=0
ax²+2bx-4x²+b+2=0
ax²-4x²+2bx+b+2=0
(a-4)x²+2bx+b+2=0
△=4b²-4(a-4)(b+2)
=4b²-4(ab-4b+2a-8)
=4(b²-ab+4b-2a+8)
x=[-b±√(b²-ab+4b-2a+8)]/(a-4)