Answer:
y = 3x - 7
Step-by-step explanation:
Slope-intercept form:
y = mx + b
Where:
y is the y value.
m is the slope.
x is the x value.
And b is the y-intercept.
First, you want to find your slope. To do this, you can either use the slope formula to find the slope, or just count on the picture:
m = rise/run
m = 3/1
m = 3
With the slope formula, you first need to choose two points.
I chose:
(2, -1) and (3, 2)
Slope formula:
m = (y2 - y1) / (x2 - x1) {It doesn't matter which point you choose to be x2 and x1, just be consistent when you plug it into the formula}
m = (2 - (-1)) / (3 - 2)
m = 3/1
m = 3
Now that you have your slope, all you need is your y-intercept. To find your y-intercept, you can either look at the graph (again) to see where the line intersects with the y-axis, or you can solve it algebraically:
y-int = -7
To solve algebraically, choose a random point on the line and plug it into what you have for your equation so far and then solve for b.
I chose:
(2, -1)
y = 3x + b
-1 = 3(2) + b
-1 = 6 + b
-1 - 6 = b
b = -7
Now you have your final answer:
y = 3x - 7
