Practice test 8 Calculator #13

First, you can plug in on this one, so if you feel rusty on your exponent rules at all, that’s a good move. Especially on the calculator section. Say, for example, that you plug in 4 for *a*. Just enter it all into your calculator (you may need to be careful with parentheses in the exponent depending on the kind of calculator you have):

Now that you know *x*, plug 0.5 into each answer choice to see which one gives you 4.

A)

B)

C)

D)

Obviously, C must be the answer.

To solve this algebraically, first start by squaring both sides. Raising a power to a power is the same as multiplying the powers, so that’ll get rid of the 1/2 on the left:

Now raise both sides to the –1 power to get *a* truly alone. Remember that a negative exponent is the same as 1 over the positive exponent, so you can transform the right hand side from to to finish the problem.