Question #7fed6

2 Answers
Oct 15, 2015

You may write radicals as fractional powers.

Explanation:

root 5 (a^4)=a^(4/5)

root 3 (a^2)=a^(2/3)

In multiplication, you add the powers, so:

root 5 (a^4)*root 3 (a^2)=a^(4/5)*a^(2/3)=a^((4/5+2/3)=

a^((12/15+10/15))=a^(22/15) so n=22/15

Oct 15, 2015

n = 22/15

Explanation:

Here's an alternative approach

root(5)(a^4) * root(3)(a^2) = a^n

Once again, the first thing to do is rewrite your radicals as exponents by using

color(blue)(root(y)(a^x) = a^(x/y))

In your case, you have

root(5)(a^4) = a^(4/5)" " and " "root(3)(a^2) = a^(2/3)

Now focus on the exponents. Find their common denominator, which in this csae is 15. You can write

4/5 * 3/3 = (12)/15" " and " "2/3 * 5/5 = 10/15

Now the equation becomes

a^(12/15) * a^(10/15) = a^n

If you want to play aroun with the exponents a bit, you can convert back to radical form

a^(12/15) = root(15)(a^12)" " and " "a^(10/15) = root(15)(a^(10))

Now you have

a^(12/15) * a^(10/15) = root(15)(a^12) * root(15)(a^(10)) = a^n

This is equivalent to

root(15)( a^12 * a^10) = a^n

Once again,

color(blue)(a^x * a^y = a^(x+y)

so you get

root(15)(a^(12 + 10)) = a^n

root(15)(a^(22)) = a^n

Finally, convert back to exponent form to get

a^(22/15) = a^n implies n = color(green)(22/15)