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12x-20y=108 3x+ky=27 what is k

User Amarildo
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1 Answer

4 votes

Let's look at the second equation and try multiplying it by 4:

4 * (3x + ky) = 4 * 27

Which gives us:

12x + 4ky = 108

This looks almost exactly like the first equation except that instead of -20y, there is 4ky. We could try making them equal to each other and solving for k:

-20y = 4ky

-20 = 4k

k = -5

Then, the answer is k = -5.

User Farhan Haque
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8.1k points