问题
解答题
先化简,再求值:
|
答案
÷(x-2+3x+3 x+2
)=2x+5 x+2
÷3(x+1) x+2 x2-4+2x+5 x+2
=3(x+1)•1 x 2+2x+1
=3(x+1)•1 (x+1) 2
=
;3 x+1
当x=cos30°-tan45°=
-1时,原式=3 2
=23 3 2
.3
先化简,再求值:
|
÷(x-2+3x+3 x+2
)=2x+5 x+2
÷3(x+1) x+2 x2-4+2x+5 x+2
=3(x+1)•1 x 2+2x+1
=3(x+1)•1 (x+1) 2
=
;3 x+1
当x=cos30°-tan45°=
-1时,原式=3 2
=23 3 2
.3