Question #625d7

1 Answer
Eddie
Jan 22, 2017

x,y = 2,1

Explanation:

A: qquad color(red)(3)x + 7y = 13
B: qquad color{red}{-9}x + 3y = -15

3 times A: qquad 9x + 21y = 39

(3 times A) + B implies qquad color(green)(9x + 21y) + color(blue)((-9x + 3y)) = color(green)(39) + color(blue)((-15))

OR:

24y = 24 implies y = 1

plug back into A:
3x + 7(1) = 13 implies x = 2

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