How do you evaluate and simplify #(120^(-2/5)*120^(2/5))/7^(-3/4)#?

1 Answer
Jul 27, 2017

See a solution process below:

Explanation:

First, use these rules of exponents to simplify the numerator:

#x^color(red)(a) xx x^color(blue)(b) = x^(color(red)(a) + color(blue)(b))# and #a^color(red)(0) = 1#

#(120^color(red)(-2/5) * 120^color(blue)(2/5))/7^(-3/4) => 120^(color(red)(-2/5)+color(blue)(2/5))/7^(-3/4) =>#

#120^color(red)(0)/7^(-3/4) => 1/7^(-3/4)#

Next, we will use this rule to rewrite the expression:

#1/x^color(red)(a) = x^color(red)(-a)#

#1/7^color(red)(-3/4) = 7^color(red)(- -3/4) = 7^(3/4)#

Then, we can rewrite the expression as:

#7^(3 xx 1/4)#

Now, we can use this rule of exponents to continue the simplification:

#x^(color(red)(a) xx color(blue)(b)) = (x^color(red)(a))^color(blue)(b)#

#7^(color(red)(3) xx color(blue)(1/4)) => (7^color(red)(3))^color(blue)(1/4) => 343^(1/4)#

Or, using this rule: #x^(1/color(red)(n)) = root(color(red)(n))(x)#

#root(4)(343)#