Question

Write the equation of the line that passes through (3, 6) and (0, –3) in slope-intercept form.

y = 3x – 6

y = 3x – 3

y = 3x + 3

y = 3x + 6

Answer 1

One thing for sure if the choices are correct, the slope m is a positive 3. As the coefficient of x in all 4 choices is a three.

Answer 2

In addition, one of the points is the y intercept, when x = 0, y is -3. My first guess is the second one. ..........But lets work it out.

Answer 3

Slope m is delta y divided by delta x. Delta means the change in x or y between the two points.

delta y= 6-(-3) = 9
delta x=3 - 0 = 3
9/3 = 3, just as we thought!

Answer 4

now using just one of the points we can develop our slope-intercept formula.

Answer 5

using the first given point (we could of used the other one= the choice is arbitrary.
6 - y
3=------
3- x
solving
9-3x=6-y
y=3x+6-9
y=3x-3 Yep looks like the second one