For example, if you know the slope of the line is 2, then your formula will look like this: y-y1 = 2(x-x1).
In our example, first you’d use the distributive property to get y-3=2x-8. Then, add 3 to each side so y is by itself. The final equation for a line in slope-intercept form with a slope of 2 that contains the point (4, 3) is y = 2x-5.
In our example, the formula would read y = 1x+b or y = x+b when you replace the slope value.
In this example, if you chose (3, 8) as your coordinates, then the formula would read 8 = 1(3)+b.
In our example, the formula currently reads 8 = 1(3)+b. Multiply 1 and 3 together to get 8 = 3+b. Since 3 is a positive number, subtract 3 from each side to isolate b. This leaves you with 5 = b, or b = 5.
For example, the equation for the line with points on (3, 8) and (7, 12) is y = 1x+5 or simply y = x+5.
