the slope-intercept form is:

Where m is the slope
b is the y-intercept
The rule to find the slope is:

The points (3, 10) and (6, 12) are on the line, so let us use them
x1 = 3, x2 = 6
y1 = 10, y2 = 12
let us substitute them in the rule of m

Substitute m in the form of the equation

To find b substitute x and y by the coordinates of any given point
let x = 3 and y = 10 (1st point)

The value of b is 8, substitute it in the equation

This is the slope-intercept form of the line passes through the given points