# How do you graph y=-2x by plotting points?

Dec 23, 2016

See Explanation

#### Explanation:

$1.$ The way to graph this with plotting points is that you choose random values for $x$ and you can find out what your $y$ value becomes.

$2.$ For example let's pick $1$, $3$, and $5$ for our $x$ values.
If you plug in those $x$ values into the function $y = - 2 x$, you get:

$y = - 2 \left(1\right)$ so your $y$ equals $- 2$.
Therefore your point on the graph is $\left(1 , - 2\right)$.

$y = - 2 \left(3\right)$ which equals $- 6$.
So another point on the graph is $\left(3 , - 6\right)$.

$y = - 2 \left(5\right)$ and that will give you $- 10$.
So there you have another point on your graph which is $\left(5 , - 10\right)$.

You can carry on plugging in different values for $x$ and see what your $y$ becomes.

$3.$ Finally you can plot and connect all the points on the graph and you will get a straight line. If that will pass through the point $\left(0 , 0\right)$, and has a slope of $- 2$ which means whichever point you pick on the line you just drew, your graph goes down $2$ and right $1$, down $2$ right $1$, down $2$ right $1$, and so on.

Here is the graph:

graph{-2x [-10, 10, -5, 5]}

Hope this helped (c: