问题
解答题
计算: (1)(-2x2y3)2•(xy)3 (2)(2x+y-1)2 (3)59.8×60.2 (4)(
(5)(7x2y3-8x3y2z)÷8x2y2 (6)1213÷(310×411) (7)4(x+1)2-(2x+5)(2x-5) (8)2x(
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答案
(1)原式=4x4y6•x3y3
=4x7y9;
(2)原式=[(2x+y)-1]2
=(2x+y)2-2(2x+y)•1+12
=4x2+4xy+y2-4x-2y+1;
(3)原式=(60-0.2)×(60+0.2)
=602-0.22
=3600-0.04
=3599.96;
(4)原式=
a3x4÷6 5
ax3-0.9ax3÷3 5
ax33 5
=2a2x-1.5;
(5)原式=7x2y3÷8x2y2-8x3y2z÷8x2y2
=
y-xz;7 8
(6)原式=1213÷(310×410×4)
=1213÷(1210×4)
=
×1231 4
=432;
(7)原式=4(x2+2x+1)-(4x2-25)
=4x2+8x+4-4x2+25
=8x+29;
(8)原式=x2-2x-x2-2x
=-4x.