+1084 You will need to know what "slope intercept" form is to solve these probelems. Basically, they are the equation of a line in this form:
y = [slope]x + [y-intercept]
Therefore, for each line, we need to find the slope and the y-intercept.
Here are a few basic things you need to know before we continue:
What is a slope?
The slope of a line is a measure of its steepness. Mathematically, slope is calculated as "rise over run" (change in y divided by change in x).
- Khan Academy
What is the y-intercept?
It is the y coordinate at the point where the line touches the y-axis.
How to tell if a slope is positive or negative?
Found these pictures on quora. The second one is a funny way to remeber:
1)
SLOPE:
To find this, let's find two points on the line: (2, 0) and (0, 3)
rise -3
We see that the -------- = ---- (AKA the difference of y over difference of x)
run 2
Y-INTERCEPT:
This is easy. It is on the graph. It basically is where the line touches the y-axis. This is at y = 3
THE EQUATION:
y = -3/2 x + 3
2)
SLOPE:
To find this, let's find two points on the line: (2, 2) and (0, 3)
rise -1
We see that the -------- = -----
run 2
Y-INTERCEPT:
This is at y = 3
THE EQUATION:
y = -1/2 x + 3
3)
SLOPE:
To find this, let's find two points on the line: (3, 3) and (0, 1)
rise 3
We see that the -------- = -----
run 2
Y-INTERCEPT:
This is at y = 1
THE EQUATION:
y = 3/2 x + 1
:)
