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I really don't like algebra, help meh with this plz if ur good at it...

I really don't like algebra, help meh with this plz if ur good at it...-example-1

2 Answers

5 votes
Ok. We have

-6x + 8y = 18

They also tell us
3x = y, which is also y = 3x (just reversed)

So we take 3x and substitute it where we see y in the first equation, then solve for x

-6x + 8(3x) = 18
-6x + 24x = 18
18x = 18
x = 1

Then we solve for y
y = 3x
y = 3(1)
y = 3

Hope this helps. LMK if you have questions.
User Marc Barbeau
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13 votes

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Answer:

(x, y) = (-1, -3)

Explanation:

You notice that the coefficient of x in the first equation is double the opposite of the coefficient of x in the second equation. This means we can make the x-term disappear by adding twice the second equation to the first.

(-6x +8y) +2(3x) = (-18) +2(y)

8y = -18 +2y . . . simplify

6y = -18 . . . . . . . subtract 2y

y = -3 . . . . . . . . . divide by 6

Substituting into the second equation, we have ...

3x = -3

x = -1 . . . . . . . . . divide by 3

The solution is (x, y) = (-1, -3).

User Nick Zinger
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4.8k points