Question

What is the value of the y variable in the solution to the following system of equations?
5x + 3y = 7
3x - 5y = -23

Answer 1

\[5x + 3y = 7\]
\[5x = 7 - 3y\]
\[x= \frac{ 7 - 3y }{ 5 }\]

Now sub in x into the second equation.

Answer 2

Thanks!!!

Answer 3

But I still don't get it.

Answer 4

Remember to put the new found y value back into the first one to get the numerical value for x

Answer 5

Alright so basically what you've done so far is isolate x in the first equation. Now you use that as your "x" value in the second equation. When you do that you'll end up with a y value. When you get this y value plug it back into the first equation and you'll get the x value. Now you have both the x and y. Lemme know if you need help

Answer 6

Ohh ok now I get it.

x=-19 and y=24

is that correct??

@SA5UK3

Answer 7

@SA5UK3

Answer 8

Umm I don't think so. Let me show you what I did

Answer 9

\[3(\frac{ 7-3y }{ 5 }) - 5y = -23\]

\[\frac{ 21-9y }{ 5 } -5y = -23\]

\[\frac{ 21-9y-25y }{ 5 } = -23\]

\[21-9y-25=-113\]

\[21-34y=-115\]

\[-34y = -136\]

\[y = \frac{ -136 }{ -34 }\]

\[y = 4\]

Answer 10

woah that's a lot of math. THANK YOU SO MUCH!!!!!!!!!!!!!!!!!!!! @SA5UK3 Your medal will be with you shortly ^-^

Answer 11

Haha, its not really a lot. I just tried to show every step. So now that you have your y value put it back into the first equation and you'll get your x.