Brad M. answered • 09/03/13

Math, Accounting, Econ, Finance, Physics, ME, EE, and Proofreading

Rob J.

asked • 09/03/13i need to find this answer out of my geometry class. it is being graded and i have no idea how to do it

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Brad M. answered • 09/03/13

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Math, Accounting, Econ, Finance, Physics, ME, EE, and Proofreading

Hey Rob -- often it's helpful simply to add the two expressions ... 2x= 8, x=4, y= -1

Sometimes subtracting will cancel out an x or y ... sometimes a formula has to be "rescaled" before adding or subtracting (I like to double or "cut in half") ... Best wishes, sir :)

Ralph L. answered • 09/03/13

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Algebra I, II, Visual Basic, Beginning C++ tutor

x + y = 3 (eq. 1)

x - y = 5 (eq. 2)

let's solve for x using eq. 2

x = y + 5 (eq. 3)

let's substitute eq. 3 into eq. 1

(y + 5) + y = 3

2y + 5 = 3

subtract 5 from both sides

2y = -2

y = -1

let's substitute value of y into eq. 3 to get x

x = -1 + 5

x = 4

therefore, **x = 4, y = -1**

Yan H. answered • 09/03/13

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Brad's method works best for this problem.

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