Question

If 3x+2y=11 and 2x+3y=17, what is the average of x and y?


A- 2.5

B- 2.8

C- 5.6

D- 5.8

E- 14

Answer 1

 

3x + 2y = 11

2x + 3y = 17

--------------------  We add the equations

5x + 5x = 28

5(x + y) = 28

x + y = 28 / 5    | ÷ 2

(x + y) / 2 = (28 / 5) / 2

(x + y) / 2 = 28 / 10

Average =   (x + y) / 2 = 2.8  

Corect answer:   B

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