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2x − y = 8 x + 2y = 4 For the system...

2x − y = 8
x + 2y = 4
For the system of equations above, what is the value of x + y ?

A

`–1`

B

4

C

5

D

20

Text Solution

Verified by Experts

The correct Answer is:
B
Multiplying both sides of the first equation in the system by 2 yields 4x − 2y = 16. Adding 4x − 2y = 16 to the second equation in the system yields 5x = 20. Dividing both sides of 5x = 20 by 5 yields x = 4. Substituting 4 for x in x + 2y = 4 yields 4 + 2y = 4. Subtracting 4 from both sides of 4 + 2y = 4 yields 2y = 0. Dividing both sides of this equation by 2 yields y = 0. Substituting 4 for x and 0 for y in the expression x + y yields 4 + 0 = 4.
Choices A, C, and D are incorrect and may result from various computation errors.
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