计算:1/x2−4x+4-x/x2−4+1/2x+4.
问题描述:
计算:
-1
x2−4x+4
+x
x2−4
. 1 2x+4
答
原式=
-1 (x−2)2
+x (x+2)(x−2)
=1 2(x+2)
=-2(x+2)−2x(x−2)+(x−2)2
2(x−2)2(x+2)
=-(x+2)(x−4) 2(x−2)2(x+2)
.x−4 2(x−2)2