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4 votes
What is the solution when-
7x-5y=14
5x+7y=64

1 Answer

4 votes

Let's eliminate the variable x first. To do this, multiply the first row of this system by 5 and mult. the second row by -7:

7x-5y=14 => 35x - 25y = 70

5x+7y=64 => -35x - 49y = -448

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- 74y = - 378. Then y = 378/74 = 5.11.

Subbing 5.11 for y in the first equation, we get: 7x - 5(5.11) = 14. Then:

7x = 14+25.55 = 39.54. Dividing both sides by 7: x = 39.54/7 = 2.71

The solution is (2.71, 5.11). If this does not agree with any of your answer choices, please double check to ensure that you've copied down the original problem correctly.

User Sacha Bruttin
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