SAT Math Multiple Choice Practice Question 451: Answer and Explanation

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Question: 451

13. If x + 2y = 20, y + 2z = 9, and 2x + z = 22, what is the value of x + y + z ?

A. 10
B. 12
C. 17
D. 22
E. 51

Correct Answer: C

Explanation:

C Stack all three equations and add them together to get 3x + 3y + 3z = 51. Factor out a 3 to get 3(x + y + z) = 51. Divide both sides by 3 to get x + y + z = 17.

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