问题
解答题
(1)计算:(1-
(2)先化简,再求值:[(2xy+3)(2xy-3)+(xy+3)2]÷xy,其中x=
|
答案
(1)原式=1-
+(-1 3
×3 2
)2011×2 3
=1-2 3
-1 3
=0;2 3
(2)原式=(4x2y2-9+x2y2+6xy+9)÷xy=(5x2y2+6xy)÷xy=5xy+6,
当x=
,y=-2时,原式=5×1 5
×(-2)+6=-2+6=4.1 5