1.
D
2.
8★6
=(8*6)/(8-6)
=48/2
=24
3.
1/36÷(1/4+1/12-7/18-1/36)+(1/4+1/12-7/18-1/36)÷1/36
=36/36*[1/36÷(1/4+1/12-7/18-1/36)]
+36/36*(1/4+1/12-7/18-1/36)÷1/36
=36*1/36÷[36*(1/4+1/12-7/18-1/36)]
+36*(1/4+1/12-7/18-1/36)÷[36*1/36]
=1÷[9+3-14-1]+(9+3-14-1)÷1
=1÷(-3)-3
=-1/3-3
=-10/3
4.
n为正整数,则(-1)2n次方=(1);(-1)2n+1次方=(-1)
5.
a^2=16
a=±4
b^2=9
b=±3
当a=4,b=3时a-b=4-3=1
当a=4,b=-3时a-b=4-(-3)=4+3=7
当a=-4,b=-3时a-b=-4-(-3)=-4+3=-1
当a=-4,b=3时a-b=-4-3=-7
6.
x2次方=(-2)2次方
x=±2
y3次方=-1
y=-1
当x=2,y=-1时
x*y^2010
=2*(-1)^2010
=2*1
=2
当x=-2,y=-1时
x*y^2010
=-2*(-1)^2010
=-2*1
=-2
当x=-2,y=-1时
x^3/y^2009
=(-2)^3/(-1)^2009
=-8/(-1)
=8
当x=2,y=-1时
x^3/y^2009
=2^3/(-1)^2009
=8/(-1)
=-8
7.
若(a-1)2次方+5取最小值,则a=(-5 )
8.
若|a|=2,则a2次方=(4),a3次方=(±8)