第十四章过关测试 (整式的乘法与因式分解)-2021秋天津【一飞冲天·小复习】八年级初二上册数学汇编测试卷

八年级上册小复习数学参考答案 第十四章过关测试 26.解:(1)x2+y2=(x+y)2-2xy =16-6 (整式的乘法与因式分解) 1.D2.A3.D4.B5.C6.C7.C8.B9.D (2)(x-y)2=(x+y)2-4xy=4 10.D 则x-y=±2, 11.D∵a=244,b=33,c=522,∴a=161,b=271,c 原式=(x+y)(x-y)=±8 25,∴b>c>a. 27.解:(1)原式=3÷5=0.6; 12.D原式=(22-1)(22+1)(24+1)…(232+1)+1 (2)原式=22m×24n=9×54=5625 (24-1)(24+1)(28+1)…(232+1)+ 28.解:(1)两个阴影图形的面积和可表示为:a2+b2或 264-1+1= (a+b)2-2ab 21=2,22=4,23=8,2+=16,2=32,26=64…个 (2)a2+b2=(a+b)2-2ab; 位数按照2,4,8,6依次循环,而64=16×4 (3)∵a,b(a>b)满足a2+b2=53,ab=14,∴①(a+ ∴原式的个位数为6 b)2=a2+b2+2ab=53+2×14=81,∴a+b=±9, x2y14.2a315.1616.169-4 又∵a>0,b>0,∴a+b=9 17.82m+5n-3=0,2m+5n=3, ∵a4-b=(a2+b2)(a+b)(a-b),(a-b)2=a2+ 4m×32n=(22)m×(25)”=22m×25m=2(2m+5m=23 b2-2ab=25;故a-b=±5 ∵a>b>0,a-b=5,∴a4-b4=(a2+b2)(a+b)(a 18.-4034 b)=53×9×5=2385 19.解:(-2a)6-(-3a3)2+[-(2a)2]3 64a6-9a6-64a 20.解:(2x+3y)2-(4x-9y)(4x+9y)+(3x-2y)2 =-3x2+94y2 21.解:(16x4-8x3+4.x2)÷(-2x)2 (16x4-8x3+4x2)÷4x2=4x2-2x+1 2.解:(x+1)(x-1)-(x-2)2 4 23.解:(1)a2+b2+4c2+2ab-4ac-4bc; (2)a2-b2-c2+2bc 24.解:(1)(x-y)2+16(y-x (x-y)-16=(x-y)(x-y-16); (2)1-a2-b2-2ab 1-(a+b)2=(1+a+b)(1-a-b); =a(a-1)(a-5) =(m2+4n2)(m2-4n2 =(m2+4n2)(m+2n)(m-2n) 25.解:(x2+nx+3)(x2-3x+m) +nx3+3 +3 =x4+(n-3)x3+(3-3n+m)x2+(mn-9)x+3m, ∵乘积中不含x2项和x3项, n-3=0,3-3n+m=0, 解得:m=6,n=3