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What is the value of x and y in the following equation?

-1x+4y=1

1x+2y=5

Guest May 2, 2017
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2+0 Answers

 #1
avatar+175 
0

The above simplified is: 4y - x = 1

                                      2y + x = 5

These 2 equations are in standard form. Let's use a method to solve it without changing them at all.

Add the 2 equations together, keeping the variables on the same side:

4y -x = 1
+ (-2y) + (-x) = + (-5)
2y + 0 = -4

 Divide each side by 2, y = -2

Put the solution for y (-2) back into each equation. Then, solve for x.

If you had needed or wanted to, you could have multiplied the bottom equation by -2 to eliminate y, then solve for x. You can multiply both equations by numbers, as long as you remember to multiply both sides by that number.

helperid1839321  May 2, 2017
 #2
avatar+76970 
+1

Just add the equations and we get :

 

6y =  6      divide both sides by 6

 

y  = 1

 

Subbing this back into either equation to find x

 

1x  + 2(1)  =  5

 

x +  2   =  5       subtract 2 from both sides

 

x  =  3

 

So   the solution set  is  { x, y }    =    { 3, 1 }

 

 

cool cool cool

CPhill  May 2, 2017

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