7x + 3y =12, 3x + 7y = 6. If (x, y) are the solutions of the system given, then what is the value of x+y?

A. 5/9
B. 9/5
C. 2
D. 4
E. 5

Answer: B

Explanation:
7x + 3y =12
3x + 7y = 6
Add the above two equations. You get,
10x+10y=18, Divide by 10,
You get, x+y=(18/10)=(9/5)

Hence, the answer is B.

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