Question

Will Medal and Fan

What is the solution to the system of equations? 5x-3y=-9
2x-5y=4

Answer 1

@One098 @Opcode @wio @TheAsker2002

Answer 2

@xo.minnie.xox

Answer 3

Can you isolate a variable in the first equation?

Answer 4

What I mean is, for: \[
5x-3y=9
\]Can you solve for \(x\) or \(y\)? Your first step is to solve for one of them.

Answer 5

5x-3y=9 x=3 and y=2

Answer 6

@wio

Answer 7

Well, that would be one solution, but we don't want to find a single solution for it, because it might not be the solution for the other equation.

Answer 8

ohh ok

Answer 9

Suppose we want to isolate \(x\). First we would add \(3y\) to both sides: \[5x = 9+3y\]Then, we would divide by \(5\): \[ x= \frac{9}{5}+\frac {3y}{5}\]

Answer 10

We can substitute this for the \(x\) in the other equations:\[
2x-5y=4
\]Will become: \[
2\left(\frac 95+\frac {3y}5\right)-5y=4
\]Now we can solve for \(y\).

Answer 11

\[
\frac{18}5+\frac{6y}5-5y = 4
\]We should multiply everything by \(5\) to get rid of fractions: \[
18+6y-25y=20
\]

Answer 12

18+6y-25y=20 so every number in this equation multiplied by 5

Answer 13

Hold on one second...

Answer 14

I made a mistake, I was using\[
5x-3y=\color{red}9
\]But I should be using \[
5x-3y=\color{red}{-9}
\]So, fixing that mistake results in: \[
-18+6y-25y=4
\]

Answer 15

Now, we can combine the like terms for \(y\) to get: \[
-18-19y = 20
\]

Answer 16

ohhh ok is that our last step to the equation?

Answer 17

Then we add \(18\): \[
-19y = 38
\]And this gives us \(y=-2\). Does that make sense?

Answer 18

Now, to solve \(x\), we substitute our solution for \(y\).\[
5x-3(-2)=-9
\]

Answer 19

Can you solve for \(x\)?

Answer 20

yes thank you for not giving me the answer and explaning :)

Answer 21

@wio how does that go to my answer choices

A.
(0, 4)

B.
(–4, 0)

C.
(0, –4)

D.
(4, 0)

Answer 22

Sorry, but those answer choices can't be for the same question.

Answer 23

Use the graph to state the solution for the system.

x – y = 4 (line a)
x + y = 4 (line b)



A.
(0, 4)

B.
(–4, 0)

C.
(0, –4)

D.
(4, 0)

Answer 24

The answer is \((x,y) = (-3,-2)\).

Answer 25

http://static.k12.com/calms_media/media/213000_213500/213096/1/adbd565410979272c1f30c00abb475ba5a33c67b/ALGTests_L2_S1_U8_Q2v2Stem.gif

Answer 26

Well, this is a separate question, but the point where they intersect is the solution.

Answer 27

And they appear to intersect at \((4,0)\).

Answer 28

Thank you for ur time! : )

Answer 29

im gonna open another question can you help me with that one to @wio

Answer 30

Sorry, but I have to go soon.