PSAT Math Multiple-Choice Question 235: Answer and Explanation

Question: 235

Based on the system of equations above, what is the value of the sum of x and y ?

• A.
• B. 3
• C.
• D. 4

Correct Answer: B

Explanation:

B

Difficulty: Medium

Category: Heart of Algebra/Systems of Linear Equations

Getting to the Answer: Solve the system of equations using substitution. Then, check that you answered the right question (find the sum of x and y). First, solve the second equation for x to get x = 3 y - 11, then substitute this expression into the first equation to find y:

Now, substitute the result into x = 3 y - 11 and simplify to find x:

The question asks for the sum, so add x and y to get , which is (B).