问题
解答题
(1)计算:(-5)0+
(2)先化简,再求值.(2x+3)(2x-3)-4x(x-1)+(x-2)2,其中x=-
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答案
(1)原式=1+2
×3
-3 3 2
=1+3-3=1;
(2)原式=4x2-9-4x2+4x+x2-4x+4
=x2-5.
当x=-
时,原式=(-3
)2-5=3-5=-2.3
(1)计算:(-5)0+
(2)先化简,再求值.(2x+3)(2x-3)-4x(x-1)+(x-2)2,其中x=-
|
(1)原式=1+2
×3
-3 3 2
=1+3-3=1;
(2)原式=4x2-9-4x2+4x+x2-4x+4
=x2-5.
当x=-
时,原式=(-3
)2-5=3-5=-2.3