Question

Solve system of equation by elimination
4x+3y=-1
5x+4y=1

Answer 1

The answer will be x = -7

Answer 2

x= -7 , y= 9

Steps:

4x+3y=-1

5x+4y=1

First, multiply the top equations by -5, and the bottom by 4 to get :

-20x-15y=5

20x+16y=4

Then, you’re going to add the two equations with them being on top of each other so you can easily see what cancels out :

-20x-15y=5

+ 20x+16y=4

———————

0+1y=9

From this, you get :

y=9

Now that you have one variable, find x by substituting 9 for y in one of the equations, I choose :

4x+3y=-1

So :

4x+3(9)=-1

Then simplify by multiplying 3 and 9 :

4x+27=-1

Then subtract 27 on each side :

4x=-28

Then, divide by 4 to get that :

x= -7

Hope this helps!!