How do you write an equation in SLOPE-INTERCEPT form of the line passing through the given points (2, 7), (1, -4)?

2 Answers
Apr 16, 2016

y=11x-15

Explanation:

The slope-intercept form is y=mx+c, where m is the slope and c is the y-intercept.

The slope is given by the change in y divided by the change in x,

(y_2-y_1)/(x_2-x_1)=(-4-7)/(1-2)=11

which gives us

y=11x+c.

Now substitute in values for x and y from the points given to find c.

-4_y=11*1_x+c
c=-15

and put this back into the equation

y=11x-15

Apr 16, 2016

y = 11x - 15

Explanation:

Slope intercept formula: y = mx + b
1) find the slope of the two points by using the formula:
(y_2 - y_1)/(x_2 - x_1) = (-4 - 7)/(1 - 2) = (-11)/-1 = 11

We now have so far: y = 11x + b

We can use a sample coordinate to find the value of b or the y-intercept (the place where the line crosses the y-axis).

We can use (2,7) where 7 = y and 2 = x.
7 = 11(2) + b

Solve for b.
7 = 11(2) + b
7 = 22 + b
7 - 22 = 22 -22 + b
-15 = b

Slope-intercept form: y = 11x - 15