Test 1 Sec 3 14 please

There are two ways to go here. First, exponent rules.

Recognize that 8=2^3, so you can rewrite \dfrac{8^x}{2^y} as \dfrac{\left(2^3\right)^x}{2^y}. Of course, that simplifies:


Because you know that 3x-y=12, you know you’ve got 2^{12}.

The other way to go is to plug in: pick values for x and y such that 3x – y = 12. For example, you may pick x = 5 and y = 3, because 3(5) – 3 = 12. Then you can evaluate \dfrac{8^5}{2^3} and match it with an answer. However, since this is the no calculator section, you may decide that this is a suboptimal way to go because the numbers are a little too big to deal with easily unless you know your exponent rules (in which case you didn’t need to plug in in the first place).

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