1. ## Absolute value graph

ABS(2x + y) - ABS(x + 3y) = 8

ABS = absolute value

I need to know where to start

2. $\displaystyle \mid2x+y\mid-\midx+3y\mid=0$

This is what we wish to solve. $\displaystyle \mid2x+y\mid-\midx+3y\mid=0$

We first must recognize that $\displaystyle \mid2x+y\mid=2x+y$ or$\displaystyle -(2x+y)$ . So, knowing this, can you finish up?

3. Originally Posted by VonNemo19
$\displaystyle \mid2x+y\mid-\midx+3y\mid=0$

This is what we wish to solve. $\displaystyle \mid2x+y\mid-\midx+3y\mid=0$

We first must recognize that $\displaystyle \mid2x+y\mid=2x+y$ or$\displaystyle -(2x+y)$ . So, knowing this, can you finish up?
it says latex error in your first two lines, idk why

4. When dealing with absolute value, you have to be aware of the folling fact-that $\displaystyle \mid{x}\mid=\mid{-x}\mid=x$ So, therefore $\displaystyle x$ can have 2 different values, but the corresponding value of $\displaystyle y$, or $\displaystyle f(x)$ will have only one. So knowing that....

We've got to set up different possibilities for the given expressions.

$\displaystyle \mid2x+y\mid=\pm(2x+y)$ and $\displaystyle \mid{x+3y}\mid=\pm(x+3y)$.

So, with this, can you take it from here?

5. $\displaystyle \sqrt{a^2+b^2}$

6. i dont really know what you want me to do? what do i do after i get +- ?
what does the square root formula have to do with this

7. Solve for y for the different possibilities and then plot your graph.

Pythagoras has nothing to do with this. I was showing my brother how to type in math code.

8. Originally Posted by VonNemo19
Solve for y for the different possibilities and then plot your graph.

Pythagoras has nothing to do with this. I was showing my brother how to type in math code.
so we do
2x + y = 8
-2x - y = 8
x + 3y = 8
-x-3y = 8

what do we do with the |2x + y| - |x + 3y| = 8

BTW this graph is on a coordinate plane, not on a number line

9. It stays right were it is. you leave everything the same but the two expressions in the inequality signs

10. Originally Posted by VonNemo19
It stays right were it is. you leave everything the same but the two expressions in the inequality signs
? i have no idea what youre talking about

is it this
2x + y - x - 3y = 8

and you also do the other 3 possible equations and just set em equal to y and graph?

Anyone can help? due tommorow