1.计算:$a^5 · a^2 · a^3 = \_\_\_\_\_\_ (a ≠ 0)$
答案
$a^{10}$
2.计算:$(ab)^4 · (-a^3)^2 ÷ (-a^2b)^3 = \_\_\_\_\_\_ (a ≠ 0,b ≠ 0).$
答案
$-a^4b$
3.计算:$(-8)^2 × (0.125)^3 = \_\_\_\_\_\_.$
答案
3. 0.125
4.计算:$0.25 × 10^n × (-4 × 10^n)^2 = \_\_\_\_\_\_$ (n为自然数)
答案
$4×10^{3n}$
5.填适当的式子使等式成立:
$x^2y^2z = -x^2y · ($
$x(y - x) = $
$x^2y^2z = -x^2y · ($
$-yz$
$)$;$x(y - x) = $
$-x$
$· (x - y)$。答案
5. $-yz,-x$
6.一个多项式与单项式$2a^2b$的积是$2a^3b - 3a^2b^2$,则这个多项式是
$a-\frac{3}{2}b$
。答案
6. $a-\frac{3}{2}b$
7.用简便方法计算:
$1002 × 998 = (\_\_\_\_\_\_)(\_\_\_\_\_\_) = \_\_\_\_\_\_.$
$1002 × 998 = (\_\_\_\_\_\_)(\_\_\_\_\_\_) = \_\_\_\_\_\_.$
答案
$1000+2,1000-2,999996$
8.已知$(x+a)(x+b)=x^2 -13x +36$,那么$ab-(a+b)$的值是
49
.答案
8. 49
9.已知$a^2 + 2a = 1$,那么$(a + 1)^2 = \_\_\_\_\_\_$
答案
9. 2
10.填适当的式子使等式成立:$x^2 + y^2 = (x - y)^2 + \_\_\_\_\_\_ = (x + y)^2 + \_\_\_\_\_\_.$
答案
$2xy,-2xy$
11.如果$a^2 - \frac{1}{3}k = (a + \frac{1}{2})(a - \frac{1}{2})$,那么$k=$
$\frac{3}{4}$
.答案
11. $\frac{3}{4}$
12.填适当的式子使等式成立:
$\frac{1}{4}x^2 - 2xy + \_\_\_\_\_\_ = (\_\_\_\_\_\_ - 2y)^2.$
$\frac{1}{4}x^2 - 2xy + \_\_\_\_\_\_ = (\_\_\_\_\_\_ - 2y)^2.$
答案
$4y^2,\frac{1}{2}x$
13.若$x^2 - 3x - 2 = (x - 1)^2 + b(x - 1) + c$,则$b=$
-1
,$c=$-4
。答案
13. $-1,-4$
14.用“因式分解”法可产生密码,如多项式$x^4 - y^4 = (x - y)(x + y)(x^2 + y^2)$,若取$x=9,y=9$时,则各因式的值为$x - y = 0, x + y = 18, x^2 + y^2 = 162$,于是就可以把“018162”作为一个六位数的密码.对于多项式$4x^3 - xy^2$,取$x=10,y=10$时,用上述方法产生的密码是
如101030,103010,301010等
.(写出一个即可)答案
14. 如101030,103010,301010等.
15. 下列计算结果正确的是 ……【 】
A.$x^3 + x^4 = x^7$
B.$x^3 · x^4 = x^7$
C.$(x^5)^5 = x^{10}$
D.$4x^3 ÷ 2x^2 = 2x^5$
A.$x^3 + x^4 = x^7$
B.$x^3 · x^4 = x^7$
C.$(x^5)^5 = x^{10}$
D.$4x^3 ÷ 2x^2 = 2x^5$
答案
B
16. 下列等式成立的是 …………【 】
A.$(-0.2a^2)^4 = 0.04a^8$
B.$[-(-3a^3)]^2 = -9a^6$
C.$-(-2a^2b)^2 = -4a^4b^2$
D.$3 · 9^m · 27^m = (3^m)^5$
A.$(-0.2a^2)^4 = 0.04a^8$
B.$[-(-3a^3)]^2 = -9a^6$
C.$-(-2a^2b)^2 = -4a^4b^2$
D.$3 · 9^m · 27^m = (3^m)^5$
答案
C
17.下列各整式的乘法运算中,计算结果正确的是 …………………………………………【 】
A.$(a+b)^2 = a^2 + b^2$
B.$(a+b)^2(a-b)^2 = a^4 - b^4$
C.$(a-b)^2 = a^2 - b^2$
D.$(a^2 + b^2)(a^2 - b^2) = a^4 - b^4$
A.$(a+b)^2 = a^2 + b^2$
B.$(a+b)^2(a-b)^2 = a^4 - b^4$
C.$(a-b)^2 = a^2 - b^2$
D.$(a^2 + b^2)(a^2 - b^2) = a^4 - b^4$
答案
D
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