How do you evaluate #5z^ -x# for z=-3 and x=2?

1 Answer
May 8, 2017

Answer:

See a solution process below:

Explanation:

First, substitute #color(red)(-3)# for #color(red)(z)# and substitute #color(blue)(2)# for #color(blue)(x)# in the expression from the problem:

#5color(red)(z)^(-color(blue)(x))# becomes:

#5 * color(red)(-3)^(-color(blue)(2))#

Now, use this rule for exponents to eliminate the negative exponent:

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

#5 * color(red)(-3)^(-color(blue)(2)) => 5 * 1/color(red)(-3)^(-color(blue)(-2)) => 5 * 1/color(red)(-3)^(color(blue)(2)) => 5 * 1/9 => 5/9#