计算:(1)-12012+(23)?1+(π-3)0-(-2)-2   (2)2m2?(-2mn)?(-12m3n3)(3)(-x3)2+(-x2

2025-08-04 20:09:30
推荐回答(1个)
回答1:

(1)-12012+(

2
3
)?1+(π-3)0-(-2)-2
=-1+
3
2
+1-
1
4

=
5
4


(2)2m2?(-2mn)?(-
1
2
m3n3
=2×(-2)×(-
1
2
)m2+1+3?n1+3
=2m6n4

(3)(-x32+(-x23-x?x5
=(-1)2?(x32+(-1)3?(x23-x1+5
=x6-x6-x6
=-x6

(4)k(k+7)-(k-3)(k+2)
=k2+7k-(k2+2k-3k-6)
=k2+7k-k2-2k+3k+6
=8k+6;

(5)(3x-2y)2-(2y-3x)(3x+2y)
=(9x2-12xy+4y2)-(6xy+4y2-9x2-6xy)
=9x2-12xy+4y2-6xy-4y2+9x2+6xy
=18x2-12xy;

(6)(2a-b+3)(2a+b-3)
=[2a-(b-3)][2a+(b-3)]
=(2a)2-(b-3)2
=4a2-(b2-6b+9)
=4a2-b2+6b-9.