Question

Write the slope-intercept form of the equation of the line which passes through the points (1, 6) and (2, 9). (

Answer 1

first you need to find the slope by using the slope formula..
slope(m) = (y2 - y1) / (x2 - x1)
(1,6) x1 = 1 and y1 = 6
(2,9) x2 = 2 and y2 = 9
now we sub
slope(m) = (9 - 6) / (2 - 1)
slope(m) = 3/1 or just 3

now we use y = mx + b (we already have all the numbers except for b, the y intercept
y = mx + b
slope(m) = 3
you can use either set of points, it does not matter. I will use (1,6) x = 1 and y = 6
now we sub and find b
6 = 3(1) + b
6 = 3 + b
6 - 3 = b
3 = b

so our equation of the line is : y = 3x + 3

any questions ?

Answer 2

good to hear....just to let you know, instead of using y = mx + b, it could have been solved with the point-slope formula, y - y1 = m(x - x1) and then turned to slope intercept form. I just find it easier to use y = mx + b unless it specifically asks for point-slope form