SAT Math Multiple Choice Question 488: Answer and Explanation

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Test Information

Question: 488

8.

If (x, y) is a solution to the system of equations above, what is the sum of x and y?

  • A.
  • B. -4
  • C.
  • D. -3

Correct Answer: B

Explanation:

B

Difficulty: Medium

Category: Heart of Algebra / Systems of Linear Equations

Strategic Advice: Because none of the variable terms has a coefficient of 1, solve the system of equations using elimination by addition (combining the equations). Before you choose an answer, check that you answered the right question (the sum of x and y).

Getting to the Answer: Multiply the top equation by 2 to eliminate the terms that have y's in them.

Now, substitute the result into either of the original equations and simplify to find y:

The question asks for the sum, so add x and y to get -3 + (-1) = -4.

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