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计算:(1)(−23)0+52+(−12)−2+(−2)3(2)x2•x4+(-x3)2-x7÷x(3)(13xy)2•(−12x2y2)÷(−43x3y)(4)5x(2x2-3x+4)(5)(3x+5)(3-2x)(6)(-2a-1)2(7)(x+2)(y+3)-(x+1)(y-2)(8)(-2p-q+1
题目详情
计算:
(1)(−
)0+52+(−
)−2+(−2)3
(2)x2•x4+(-x3)2-x7÷x
(3)(
xy)2•(−12x2y2)÷(−
x3y)
(4)5x(2x2-3x+4)
(5)(3x+5)(3-2x)
(6)(-2a-1)2
(7)(x+2)(y+3)-(x+1)(y-2)
(8)(-2p-q+1)(-q+2p-1)
(9)(x-y)2-(x+y)(x-y)
(10)[(x+y)2-(x-y)2]÷(2xy)
(1)(−
2 |
3 |
1 |
2 |
(2)x2•x4+(-x3)2-x7÷x
(3)(
1 |
3 |
4 |
3 |
(4)5x(2x2-3x+4)
(5)(3x+5)(3-2x)
(6)(-2a-1)2
(7)(x+2)(y+3)-(x+1)(y-2)
(8)(-2p-q+1)(-q+2p-1)
(9)(x-y)2-(x+y)(x-y)
(10)[(x+y)2-(x-y)2]÷(2xy)
▼优质解答
答案和解析
(1)(-
)0+52+(-
)-2+(-2)3
=1+25+4+(-8)
=30-8
=22;
(2)x2•x4+(-x3)2-x7÷x
=x6+x6-x6
=x6;
(3)(
xy)2•(-12x2y2)÷(-
x3y)
=
x2y2•(-12x2y2)•(-
)
=4xy3;
(4)5x(2x2-3x+4)
=10x3-15x2+20x;
(5)(3x+5)(3-2x)
=9x-6x2+15-10x
=-6x2-x+15;
(6)(-2a-1)2
=(2a+1)2
=4a2+4a+1;
(7)(x+2)(y+3)-(x+1)(y-2)
=xy+3x+2y+6-(xy-2x+y-2)
=xy+3x+2y+6-xy+2x-y+2
=5x+y+8;
(8)(-2p-q+1)(-q+2p-1)
=[-q-(2p-1)][-q+(2p-1)]
=(-q)2-(2p-1)2
=q2-(4p2-4p+1)
=q2-4p2+4p-1;
(9)(x-y)2-(x+y)(x-y)
=(x2-2xy+y2)-(x2-y2)
=x2-2xy+y2-x2+y2
=2y2-2xy;
(10)[(x+y)2-(x-y)2]÷(2xy)
=[(x2+2xy+y2)-(x2-2xy+y2)]÷2xy
=4xy÷2xy
=2.
2 |
3 |
1 |
2 |
=1+25+4+(-8)
=30-8
=22;
(2)x2•x4+(-x3)2-x7÷x
=x6+x6-x6
=x6;
(3)(
1 |
3 |
4 |
3 |
=
1 |
9 |
3 |
4x3y |
=4xy3;
(4)5x(2x2-3x+4)
=10x3-15x2+20x;
(5)(3x+5)(3-2x)
=9x-6x2+15-10x
=-6x2-x+15;
(6)(-2a-1)2
=(2a+1)2
=4a2+4a+1;
(7)(x+2)(y+3)-(x+1)(y-2)
=xy+3x+2y+6-(xy-2x+y-2)
=xy+3x+2y+6-xy+2x-y+2
=5x+y+8;
(8)(-2p-q+1)(-q+2p-1)
=[-q-(2p-1)][-q+(2p-1)]
=(-q)2-(2p-1)2
=q2-(4p2-4p+1)
=q2-4p2+4p-1;
(9)(x-y)2-(x+y)(x-y)
=(x2-2xy+y2)-(x2-y2)
=x2-2xy+y2-x2+y2
=2y2-2xy;
(10)[(x+y)2-(x-y)2]÷(2xy)
=[(x2+2xy+y2)-(x2-2xy+y2)]÷2xy
=4xy÷2xy
=2.
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