How do I use the addition method to solve this?

4x - y = 3

2x + 3y = 19

SmartMathMan Apr 30, 2019

#1**0 **

By addition method, it is the same thing as elimination, which is what it is officially called.

Elimination:

So we can mulitply the bottom equation by 2 so that we can then cancle out the "x's" later on

(2x+3y=19)*2

4x+6y=38

Now we have the two equations

4x-y=3 , 4x+6y=38

We can then subtract these two equations to cancel out the "x"

4x-y-(4x+6y)=3-38

-y-6y=-35

-5y=-35

5y=35

y=7

So now we have figured out our y value is 7, and we can substitute it into our equation to get our "x" value now.

4x-7=3

4x=10

x=5/2 or 2.5

doorknoob Apr 30, 2019