第三周周侧1.下列各式中,相等关系一定成立的是( )A.(x-y)2=(y-x)2 B.(x+6)(x-6)=x2-6C.(x+y)2=x2+y2 D.6(x-2)+x(2-x)=(x-2)(x-6)2.下列运算正确的是( )A.x2+x2=2x4 B.a2•a3= a5C.(-2x2)4=16x6 D.(x+3y)(x-3y)=x2-3y23.下列计算
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![第三周周侧1.下列各式中,相等关系一定成立的是( )A.(x-y)2=(y-x)2 B.(x+6)(x-6)=x2-6C.(x+y)2=x2+y2 D.6(x-2)+x(2-x)=(x-2)(x-6)2.下列运算正确的是( )A.x2+x2=2x4 B.a2•a3= a5C.(-2x2)4=16x6 D.(x+3y)(x-3y)=x2-3y23.下列计算](/uploads/image/z/4523342-14-2.jpg?t=%E7%AC%AC%E4%B8%89%E5%91%A8%E5%91%A8%E4%BE%A71.%E4%B8%8B%E5%88%97%E5%90%84%E5%BC%8F%E4%B8%AD%2C%E7%9B%B8%E7%AD%89%E5%85%B3%E7%B3%BB%E4%B8%80%E5%AE%9A%E6%88%90%E7%AB%8B%E7%9A%84%E6%98%AF%28+%29A.%28x-y%292%3D%28y-x%292+B.%28x%2B6%29%28x-6%29%3Dx2-6C.%28x%2By%292%3Dx2%2By2+D.6%28x-2%29%2Bx%282-x%29%3D%28x-2%29%28x-6%292.%E4%B8%8B%E5%88%97%E8%BF%90%E7%AE%97%E6%AD%A3%E7%A1%AE%E7%9A%84%E6%98%AF%28+%29A.x2%2Bx2%3D2x4+B.a2%26%238226%3Ba3%3D+a5C.%28-2x2%294%3D16x6+D.%28x%2B3y%29%28x-3y%29%3Dx2-3y23.%E4%B8%8B%E5%88%97%E8%AE%A1%E7%AE%97)
第三周周侧1.下列各式中,相等关系一定成立的是( )A.(x-y)2=(y-x)2 B.(x+6)(x-6)=x2-6C.(x+y)2=x2+y2 D.6(x-2)+x(2-x)=(x-2)(x-6)2.下列运算正确的是( )A.x2+x2=2x4 B.a2•a3= a5C.(-2x2)4=16x6 D.(x+3y)(x-3y)=x2-3y23.下列计算
第三周周侧
1.下列各式中,相等关系一定成立的是( )
A.(x-y)2=(y-x)2 B.(x+6)(x-6)=x2-6
C.(x+y)2=x2+y2 D.6(x-2)+x(2-x)=(x-2)(x-6)
2.下列运算正确的是( )
A.x2+x2=2x4 B.a2•a3= a5
C.(-2x2)4=16x6 D.(x+3y)(x-3y)=x2-3y2
3.下列计算正确的是( )
A.(-4x)•(2x2+3x-1)=-8x3-12x2-4x B.(x+y)(x2+y2)=x3+y3
C.(-4a-1)(4a-1)=1-16a2 D.(x-2y)2=x2-2xy+4y2
4.(x+2)(x-2)(x2+4)的计算结果是( )
A.x4+16 B.-x4-16 C.x4-16 D.16-x4
5.19922-1991×1993的计算结果是( )
A.1 B.-1 C.2 D.-2
6.对于任意的整数n,能整除代数式(n+3)(n-3)-(n+2)(n-2)的整数是( )
A.4 B.3 C.5 D.2
7.( )(5a+1)=1-25a2,(2x-3) =4x2-9,(-2a2-5b)( )=4a4-25b2
8.99×101=( )( )= .
9.(x-y+z)(-x+y+z)=[z+( )][ ]=z2-( )2.
10.多项式x2+kx+25是另一个多项式的平方,则k= .
11.(a+b)2=(a-b)2+ ,a2+b2=[(a+b)2+(a-b)2]( ),
a2+b2=(a+b)2+ ,a2+b2=(a-b)2+ .
12.计算.(1)(a+b)2-(a-b)2;
(2)(3x-4y)2-(3x+y)2;
(3)(2x+3y)2-(4x-9y)(4x+9y)+(2x-3y)2;
(4)1.23452+0.76552+2.469×0.7655;
(5)(x+2y)(x-y)-(x+y)2.
13.已知m2+n2-6m+10n+34=0,求m+n的值
14.如果(2a+2b+1)(2a+2b-1)=63,求a+b的值.
15.已知(a+b)2=60,(a-b)2=80,求a2+b2及ab的值.
第三周周侧1.下列各式中,相等关系一定成立的是( )A.(x-y)2=(y-x)2 B.(x+6)(x-6)=x2-6C.(x+y)2=x2+y2 D.6(x-2)+x(2-x)=(x-2)(x-6)2.下列运算正确的是( )A.x2+x2=2x4 B.a2•a3= a5C.(-2x2)4=16x6 D.(x+3y)(x-3y)=x2-3y23.下列计算
(1)A(2)B(3)C(4)C(5)A(6)C(7)1-5a 2x+3 -2a2+5b (8)(100-1)(100+1)=9999
(9) [z+(x-y)][z-(x-y)]=z2-(x-y)2 (10) 10 (11) 4ab 1/2 -2ab 2ab
(12) (a+b)2-(a-b)2=a2+2ab+b2-a2+2ab-b2=4ab
(3x-4y)2-(3x+y)2=9x2-24xy+16y2-9x2-6xy-y2=15y2-30xy
你那个后面的2是平方还是乘2?