Question

Did I do this problem right?
Solve the linear system:
4x+3y=1 and -3x - 6y = 3

7x - 9y = -2

Answer 1

Nope.

Answer 2

You need to find an \(x\) and \(y\) value.

Answer 3

First eliminate the \(y\) values.

Answer 4

Since you have \(3y\) and \(-6y\).
As things stand \(3y-6y=-3y\).
However if you multiply the first one by \(2\) then \((2)3y-6y=6y-6y=0\).

Answer 5

So we multiply the first equation by \(2\).\[
4x+3y=1 \to 8x+6y=2
\]

Answer 6

Now you can add the equations: \[
\begin{split}
&8x&+& 6y &=& 2 \\
+&-3x& -& 6y &=& 3\\
&5x&&&=&5
\end{split}
\]This means \(x=1\)

Answer 7

x = 1 and y = -1

Answer 8

okay so how do you get y?!

Answer 9

plug in 1 for x and solve for y

Answer 10

To get \(y\) you plug \(1\) into \(x\) for either equation: \[
-3x - 6y = 3\\
-3(1) - 6y = 3
\]

Answer 11

C?

Answer 12

yes, so just to make sure im writing it correctly, its (1,-1) ?

Answer 13

yes

Answer 14

U r correct!

Answer 15

thank you very much to the both of you!

Answer 16

A/t else I can help u w/?

Answer 17

um, let me see

Answer 18

I am ready

Answer 19

what is the slope of the line of 4x-5y=9?

Answer 20

Lets work it together, Do u know the slope formula?

Answer 21

y=mx+b ?

Answer 22

Ok

Answer 23

Try to put this equation in a standard format
(like y=mx+b)

Answer 24

Do u know how to do this?

Answer 25

y=4x+5?

Answer 26

the original equation was 4x-5y=9, and how did you get this, no!....
basically solve for y (in terms of x)

Answer 27

but 4 doesnt go into 9, im so confused!

Answer 28

OK!
4x-5y=9
5y=9+4x
y = 9/5 + 4/5x
(lets put is in a standard form the same way as y=mx+b)
y= 4/5x +9/5

Answer 29

Now answer the following for me, what is the slope and what is the y intercept?

Answer 30

i honestly have no idea, i dont get this.

Answer 31

What don't u get?

Answer 32

A/t?

Answer 33

lets follow the steps together. STEP 1
4x-5y=9
Do u understand y i did this?

Answer 34

I wrote the equation out, next...

Answer 35

5y=9+4x
what am I doing in this STEP ? do u know?

Answer 36

oh i do know that you have to put y first.

Answer 37

Yes there u go! Eliminate the Y
so i preformed the following steps
4x-5y=9
5y=9+4x
y = 9/5 + 4/5x
(lets put is in a standard form the same way as y=mx+b)
y= 4/5x +9/5

Answer 38

C ?

Answer 39

kinda so how do you add the 4/5x + 9/5?

Answer 40

I don't add 4/5x + 9/5, I can't and I don't have to!

Once I have this equation- y= 4/5x +9/5 , I am done!

Compare this to y=mx+b
and tell me, in the equation that I got, what is the slope?

Answer 41

so it would just be 4/5?

Answer 42

Yes! CORRECT!

Answer 43

THANK YOU!

Answer 44

and the Y intercept would be what?