SOLUTION: i need to know y and x i found x=-3 i cant find y the problem is -4x-3y=3 -2x+5y=21

Question 299353: i need to know y and x i found x=-3 i cant find y
the problem is
-4x-3y=3
-2x+5y=21
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!

Start with the given system of equations:

Multiply the both sides of the second equation by -2.

Distribute and multiply.

So we have the new system of equations:

Now add the equations together. You can do this by simply adding the two left sides and the two right sides separately like this:

Group like terms.

Combine like terms.

Simplify.

Divide both sides by to isolate .

Reduce.

------------------------------------------------------------------

Now go back to the first equation.

Plug in .

Multiply.

Add to both sides.

Combine like terms on the right side.

Divide both sides by to isolate .

Reduce.

So the solutions are and .

Which form the ordered pair

.

This means that the system is consistent and independent.

Notice when we graph the equations, we see that they intersect at

. So this visually verifies our answer.

Graph of (red) and (green)

RELATED QUESTIONS
i cant factor 2x^2+5x-7. i need to find the dicontinuity of this problem... (answered by lynnlo)

What would X= And what would Y= if, -2x - 3y = -3 and 4x + 5y = 3 I Dont... (answered by stanbon)

I really need help.I need to know the right answer on this problem. Elimination... (answered by ewatrrr)

I really need help multiplying rational expressions. I have tried it, i just mainly need (answered by Alan3354)

I NEED TO SEE HOW THIS PROBLEM IS WORKED OUT I KNOW THE ANSWER IS 15X+15Y... (answered by stanbon)

I cant get the right answer for y i know x = 0 can someone help me find y Use the... (answered by ewatrrr)

find value of x and y 1.) 2x+5y=-9 3x-4y=-2 2.) 4x+13y=40 4x+3y=-40 3.) (answered by stanbon)

Please help me to write y=3/4x+2 in standard form. I know that I need the x and Y... (answered by richwmiller)

I need help in doing this. For which system(s)is (2,3)the solution? I know I have to... (answered by elima)