Question

How would you graph y=x+4 using slope and y-intercept?

Answer 1

The slope is the coefficient in front of the x. In this case, the coefficient is one so the slope is 1. (When you graph the line, the line will rise by 1 for every time it goes to the right by 1.) Notice the +4 at the end of the equation. This means that the point where x=0, y will be equal to 4.

To graph this, start with x=0 and find x. Then, solve the equation using x=1, x=2, etc...

graph{x+4 [-10, 10, -5, 5]}

Answer 2

Here's what the graph should look like: graph{y=x+4 [-7.754, 4.736, -0.625, 5.62]}

Explanation:

The equation already in the slope-intercept form of a line, `y=mx+b`, where `m` is the slope and `b` is the y-intercept.
In this equation, `m=1` and `b=4`.

Okay, so start with the y-intercept. If `b=4`, then the point (0,4) is where it crosses the y-axis.

Now there are two ways you could continue. Either: 1) make a table, pick x values and plug them into the equation and solve for y values, or 2) use the slope to draw the line.

Let's use the slope to draw the line.
Because the slope is 1, we know the `(rise)/(run)=1/1`. For every step you go up, you also run to the right. For example, if you go up to 5, you go over to 1: `(1,5)`. Plot more values like this, and when you see the pattern, you can draw the line through the points: