Question

Verify that (-4, 12) is the solution to the system. Show work to justify your answer

Answer 1

Equation 1) 2x + y = 5
Equation 2) -5x - 2y = -6

Multiply equation 1 by 2, so that both equations have (2y) in it.

1)  2 (2x + y = 5)

1)  4x + 2y = 10
2)  -5x - 2y = -6

Add equations together.

x=-4

Plug in (-4) for x in equation 1.

2x + y = 5

2(-4) + y = 5

-8 + y = 5

Add 8 to both sides of the equation.

y = 13

(-4, 13)

So no, (-4, 12) is not the correct answer.

~Hope I helped!~

Answer 2

2x+y=5 and -5x-2y=-6

Multiply the 1st equation by 2 and you have:

4x+2y=10 now add this to the second equation which cancels out y...you are left with:

-x=4, divide both sides by -1 so that x=-4 

Now use either original equation to find y using the value of x that we just found...2x+y=5 becomes:

-8+y=5  add 8 to both sides

y=13

So the solution is (-4,13) and NOT (-4,12)