PSAT Math Multiple-Choice Practice Question 294

Correct Answer: A

Explanation:

A

Difficulty: Medium

Category: Solving Equations

Strategic Advice: You have two variables, but only one equation, so solving for each variable will not be possible. Instead, pick numbers for x and y that will make the equation true.

Getting to the Answer: Pick a simple number for x and solve for y. Hopefully, y will also be easy to work with so you can plug them into the expression you are trying to find. Say x = 4; this gives , or Multiplying both sides by 2 y gives 12 = 12 y, so y = 1. Both numbers are very manageable, so plug them into the expression . This yields , which is (A).