幂的乘方数学题!
问题描述：
幂的乘方数学题!
1.若3x+5y=3,则8^x*32^y=()
2.2*8^n*(4^n)^2=256 求N.
答
1.3x+5y = 3
(8^x)*(32^y) = [(2^3)^x]*[(2^5)^y] = (2^3x)*(2^5y) = 2^(3x+5y) = 2^3 = 8
2.2*8^n*(4^n)^2 = 2*[(2^3)^n]*[(2^2)^n]^2 = 2 * 2^3n * 2^4n = 2^(1+7n) = 256 = 2^8
7n+1 = 8, n = 1