救命!byrewritingeachpartoftheexpressionsandthenusingindexlaws,reduceeachofthefollowingtosimplestfroma）9^3/3^Nb)4^2n/2^3乘以2^n+1/8c)25/5^n+1乘以5^2n/125

Question

救命!
by rewriting each part of the expressions and then using index laws,reduce each of the following to simplest from
a）9^3 / 3^N
b) 4^2n / 2^3 乘以 2^n+1 / 8
c ) 25 / 5^n+1 乘以 5^2n / 125

Answer 1

重写多项式,把它们简化了
又不是选择题,选什么A
a)
3^6 / 3^N
=3^(6-N)
b)
2^2n / 2^3 × 2^(n+1)/2^3
=2^(2n-3) × 2(n-2)
=2^(3n -5)
c)
5^2 / 5^(n+1) × 5^2n/5^3
=5^(1-n) × 5(2n - 3)
=5^(n-2)