# How do you graph y=2x-1 by plotting points?

Jul 4, 2016

Calculating two points and drawing the line between the two.

#### Explanation:

When the exponents of the variables are all $1$, that is there are no square, cubes, etc. the equation is a line.
Then it is enough to find two points to draw it.
We can calculate two points assigning a number to $x$ and calculating the corresponding number for $y$.
For example, when $x = 0$ $y = 2 \cdot 0 - 1 = - 1$. Then the line will pass from the point $\left(0 , - 1\right)$. We need a second point, we can take $x = 1$, then $y = 2 \cdot 1 - 1 = 1$. The line will pass from $\left(1 , 1\right)$. We can mark the two points on the plane and draw the line passing from these two points. Jul 4, 2016

To find the y-intercept, put x = 0
y = 2 (0) - 1
y = -1
To find the x-intercept, put y = 0
2x - 1 = 0
2x = 1
x = 1/2
Draw your system of axis. Mark -1 on the y-axis, and 1/2 on the x-axis.
Now draw a line through these two ponts. Add arrows.
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To draw the graph by using points,
let x = -1, then y = 2 (-1) - 1 = -2 - 1 = -3
first point is (-1; -3)
Let x = 0, y = 2 (0) - 1 = -1
Second point is (0; -1)
Let x = 1, y = 2(1) - 1 = 1
Third point is (1; 1)
Plot the three points and draw a line through them. Add arrows to your line.