If you wanted to eliminate the y variable by adding the two equations in the following system, what could be your first step?

x − y = 6
4x − 3y = 12

Question

If you wanted to eliminate the y variable by adding the two equations in the following system, what could be your first step?

  x − y = 6
4x − 3y = 12

zepp · Answer

You have to make a 3y appear in your first equation, or, make the 3 disappear in the second equation.

zepp · Answer

$$\frac{4x − 3y = 12}{3}\rightarrow\frac{4}{3}x-y=4$$

zepp · Answer

Or,  (x − y = 6)3 $\rightarrow$ 3x-3y=18

anonymous · Answer

Add the two equations together 

 Multiply the first equation by −4 

 Multiply the first equation by 3 

 Multiply the first equation by −3

zepp · Answer

Oh, adding up.

Then
 (x − y = 6)-3=-3x+3y=-18

zepp · Answer

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