x^a=1,x^b=4,求x^3a+2b的值

题目

x^a=1,x^b=4,求x^3a+2b的值
x^2n=3,(x^3n)^4=______
已知10^a=5,10^b=6,求10^3a+2b的值
已知n为正整数,且x^2n=4,试求9(x^3n)^2-13(x^2)^2n的值

答案

x^a=1,x^b=4,求x^3a+2b的值
x^(3a+2b)
=x^3a*x^2b
=(x^a)^3*(x^b)^2
=16
x^2n=3,(x^3n)^4=______
(x^3n)^4
=(x^3n)^2*(x^3n)^2
=(x^2n)^3*(x^2n)^3
=729
已知10^a=5,10^b=6,求10^3a+2b的值
10^(3a+2b)
=10^3a*10^2b
=(10^a)^3*(10^b)^2
=4500
已知n为正整数,且x^2n=4,试求9(x^3n)^2-13(x^2)^2n的值
9(x^3n)^2-13(x^2)^2n
=9(x^2n)^3-13(x^2n)^2
=576-208
=368