1、八年级上整式的运算乘法公式练习题1.下列各式中,相等关系一定成立的是( )A.(x-y)2=(y-x)2B.(x+6)(x-6)=x2-6C.(x+y)2=x2+y2D.6(x-2)+x(2-x)=(x-2)(x-6)2.下列运算正确的是( )A.x2+x2=2x4B.a2a3= a5C.(-2x2)4=16x6D.(x+3y)(x-3y)=x2-3y23.下列计算正确的是( )A.(-4x)(2x2+3x-1)=-8x3-12x2-4xB.(x+y)(x2+y2)=x3+y3C.(-4a-1)(4a-1)=1-16a2D.(x-2y)2=x2-2xy+4y24.(x+2)(x-2)(x2+4
2、)的计算结果是( )A.x4+16B.-x4-16C.x4-16D.16-x45.19922-19911993的计算结果是( )A.1B.-1C.2D.-26.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.4B.3C.5D.27.( )(5a+1)=1-25a2,(2x-3) =4x2-9,(-2a2-5b)( )=4a4-25b28.99101=( )( )= .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
3、+(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+2.4690.7655;(5)(x+2y)(x-y)-(x+y)2.13.已知m2+n2-6m+10n+34=0,求m+n的值14.已知a+=4,求a2+和a4+的值.15.如果(2a+2b+1)(2a+2b-1)=63,求a+b的值.16.已知(a+b)2=60,(a-b)2=80,求a2+b2及ab的值.17.观察下面各式:12+(12)2+22=(12+1)222+(22)2+32=(23+1)232+(34)2+42=(34+1)2(1)写出第2005个式子;(2)写出第n个式子,并说明你的结论.5 / 5