Test 1 Sec 3 14 please
There are two ways to go here. First, exponent rules.
Recognize that , so you can rewrite as . Of course, that simplifies:
Because you know that , you know you’ve got .
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 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).