Solve the system for y: 3x - 5y = -9, 4x + 5y = 23

So we have:

\(\displaystyle \L 3x-5y=-9\)
\(\displaystyle \L 4x+5y=23\)

Which I simplified to make it easier to use the Addition Method:

\(\displaystyle \L -5y = -9 -3x\)
\(\displaystyle \L 5y=23- 4x\)

Add these together solve for \(\displaystyle \L x\) and then fill it back into one of your original equation for \(\displaystyle \L y\).

It is just that simple. :D
 
I have no idea how to read what you posted. I'm going to re-read my book, will have to get back to you on this one.
 
Yeah that would help immensely.

Then add the y's, the x's and the intergers together in these two equations gettin one equation that will be equal to 0.

\(\displaystyle \L -5y = -9 -3x\)
\(\displaystyle \L 5y=23- 4x\)
 
But this method may not be in your book cuz it was not in mine. You could just get both equation equal to x or y but it would be much more difficult and messy.
 
Re: Solve the system for y:

redranger7018 said:
Solve the system y:

3x - 5y = -9

4x + 5y = 23 "add" the two equations together, term for term ...
----------------
7x = 14
x = 2

now substitute 2 for x in either equation and solve for y




Answer ?
 
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