Question

2x+y=8, x-y=1

Answer 1

write it like this.
2x+y=8
x-y=1

add the two functions together.
(2x+x) + (y-y) = (8+1)
3x = 9
x = 3

plug x = 3 back into one of the two equations (x-y=1)

3-y = 1
-y=1-3
y = 2

Answer 2

writing the two functions. one on top of the other.

Answer 3

https://www.khanacademy.org/math/algebra/systems-of-eq-and-ineq/solving-systems-addition-elimination/v/solving-systems-by-elimination

Answer 4

yw

Answer 5

You want to set up a matrix such that:

\[\left( A:b \right)\]

where A is the matrix where the coefficients of x and y are in the rows:

\[A=\left[\begin{matrix}2 & 1 \\ 1 & -1\end{matrix}\right]\]

and
\[b=\left(\begin{matrix}8 \\ 1\end{matrix}\right)\]

So if Ax = b then solve the matrix of:

\[\left[\begin{matrix}2 & 1 & 8 \\ 1 & -1 & 1\end{matrix}\right]\]

Answer 6

2x+y=8 ___x =____?
x-y= 1

Answer 7

_____x = 9 How do I find the x?

Answer 8

Question: Do you want this category to be Linear Algebra?

In other words, are you trying to solve the equations anyway you can or in an easy matrix row reduction?

The first way you can follow along with Tomo, the second with myself.

Answer 9

this is an algebra question. what grade are you in @tootlescar47?

Answer 10

I am doing a self help quiz and the question is above I am trying to find the value of x! I am taking on-line courses for college!

Answer 11

I think @malical is just over complicating a simple algebra problem. you definitely do not need linear algebra to solve this.

Answer 12

Yes, I am over complicating it. But if the goal is to learn how matrices and systems of equations work then the process > answer.

Answer 13

Lets not fussI I can really use both of your help! I have 5 more question that I need help with please!

Answer 14

_____x = 9 How do I find the x? I figured out the last part of the equation but I need to find the x value!

Answer 15

I'm sorry. I don't understand what you are typing in. Maybe show the steps that led you to this conclusion?

Answer 16

2x+y=8 ___x = 9
x-y= 1

Answer 17

2x+y=8
x-y=1

add the two functions together.
(2x+x) + (y-y) = (8+1)
3x = 9
x = 3

plug x = 3 back into one of the two equations (x-y=1)

3-y = 1
-y=1-3
y = 2

So now I have to solve equation for y to obtain the slope-intercept form of the equation.
2x+y=8 ---> y=?
x-y= 1 ----> y=?

Answer 18

Well, solve for y?

x-y=1
x=1+y
x-1=y

and the same idea for the second one.

Answer 19

Thank You!