What is the value ofx ifx^(4/5)=(2^8)/(3^8)?

3 Answers
Mar 18, 2017

x=1024/59049

Explanation:

If x > 0 and a, b are any real numbers, then:

(x^a)^b = x^(ab)

So we find:

x = x^1 = x^(4/5*5/4) = (x^(4/5))^(5/4)=(2^8/3^8)^(5/4)= ((2/3)^8)^(5/4) = (2/3)^(8*5/4) = (2/3)^10 = 2^10/3^10=1024/59049

Mar 18, 2017

x=(2/3)^10

Explanation:

In general if x^a=p^b then
color(white)("XXX")x=(x^a)^(1/a) = (p^b)^(1/a)

In this case
color(white)("XXX")a = 4/5color(white)("XX")rarrcolor(white)("XX")1/a=5/4

color(white)("XXX")p=2/3
and
color(white)("XXXXXX")after noting that (2^8)/(3^8)=(2/3)^8
color(white)("XXX")b=8

So
color(white)("XXX")x=((2/3)^8)^(5/4) = (2/3)^((8 * 5)/4) = (2/3)^10

Mar 18, 2017

x=0.01734152

Explanation:

x^(4/5)=(2^8)/3^8

Make x radical,

root(5)(x^4)=2^8/3^8

Multiply both sides by the index of 5,

(root(5)(x^4))^5=(2^8/3^8)^5
x^4=2^40/3^40

Root both sides by index of 4,

root(4)(x^4)=root(4)(2^40/3^40)
(x^4)^(1/4)=(2^40/3^40)^(1/4)
x=2^10/3^10
x=1024/59049

Hence x=0.01734152.