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What is one of the solutions to the following system of equations? y2 + x2 = 53. y − x = 5. A. (−10, −5) B. (−7, −2) C. (7, 2) D. (5, 10)

1 Answer

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Answer is (-7, -2)

Rewrite the equations so that both are set equal to 0:
y^2 + x^2 = 53
y^2 + x^2 - 53 = 0

y - x = 5
y - x - 5 = 0

Set them equal to eachother:
y^2 + x^2 - 53 = y - x - 5
y^2 + x^2 = y - x + 48
Plug in the value options and see which one works.
A) (-10, -5)
25 + 100 = -5 + 10 + 48 Does not work, eliminate option

B) (-7,-2)
4 + 49 = -2 + 7 + 48
53 = 53 We have a match!
We can stop checking now, we've found the coordinate pair that solves.

Answer is B) (-7, -2)
User Jae Sung Chung
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