同底数幂的题目
问题描述：
同底数幂的题目
1.x^3m-n*x^2m-3n*x^n-m2.[-2]*[-2]^2*[-2]^3*.*[-2]^100 3.4*2^a*2^a+1=2^9,且2a+b=8,求a^b的值
答
1.
x^(3m-n)*x^(2m-3n)*x^(n-m)=
=x^(3m-n+2m-3n+n-m)
=x^(4m-3n)
2.
[-2]*[-2]^2*[-2]^3*.*[-2]^100
=[-2]^(1+2+3+.+100)
=[-2]^[(1+100)*100/2]
=[-2]^5050
3.
4*2^a*2^(a+1)=2^9,
4*2^[2+a+(a+1)]=2^9,
即,2+a+(a+1)=9,
解出,a=3
代入2a+b=8,
b=8-2a=8-2*3=2
所以,
a^b=3^2=9