X^+4x+4=1+4

(X+2)^=5

x+2=正負根號5

X=正負根號5-2

x²+4x+4=1+4

(x+2)²=5

x+2=√5

x=√5-2

x²+4x+4=5

（x+2）²=5

（X+2）²=5

X+2=±√￣5

X=±√￣5—2

x²+4x+4=5

-4x+x²=-1.75

x²-4x=-1.75

x²-4x+4=-1.75+4

(x-2)²=2.25

x-2=±1.5

x=3.5或x=0.5

x²-4x=0

x(x-4)=0

x=0或4

(x-1)²-2(x-1)=0

(x-1)(x-1-2)=0

(x-1)(x-3)=0

原式=[(x²+4x+4-x(x+2)]/(x+2)(x-2)

=(x²+4x+4-x²-2x)/(x+2)(x-2)

=2(x+2)/(x+2)(x-2)

=2/(x-2)

x=1或3

4-x2-2xy-y2=4－（x²＋2xy＋y²）=2²－(x＋y)²=(2＋x＋y)(2－x－y)不懂還可問,o(∩_∩)o