Question

1 MEDAL HELP PLEASE AS SOON AS POSSIBLE.
Select the best possible first step to solving the system by first eliminating the x variable.


3x - 9y = 6
2x - 11y = 6

Answer 1

@maaryliin
Please post the steps >>>Select the best possible first step

Answer 2

multiplying equation 1 by -2/3
or
multipling eq 2 by -3/2

Answer 3

1) 3x - 9y = 6
Multiply by -2/3
-2/3 * 3x -2/3 * (-9)y = (-2/3)*6
1* -2x + 6y = -4

Compare 1* with Equation 2

1*) -2x + 6y = -4
2) 2x - 11y = 6
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Notice that the x terms -2x and 2x add to 0x and the x-term is eliminated.

Answer 4

But, in applying the other option, multipling eq 2 by -3/2, something similar happens.

2) 2x - 11y = 6
(-3/2)*(2x) - 11(-3/2) = (-3/2)6
2**) -3x +(33/2)x = -9

Now compare 2**) with 1)

1) 3x - 9y = 6
2**) -3x +(33/2)x = -9
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Notice that the x variables in both equation are now easily eliminated by addition as with the first option.

So, which is better? It is not clear.

I think it may have to do with avoiding fractions.

Answer 5

Add all terms here and see how easily, or not, it is to solve for y.

1* with Equation 2
1*) -2x + 6y = -4
2) 2x - 11y = 6
--------------------

Then do the same with these two:

1) 3x - 9y = 6
2**) -3x + (33/2)x = -9
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@maaryliin Post what you decide, okay?