Question

The points (3, r) and (15, -2) lie on the line with slope 3/2. Find the missing coordinate r.

A) r = -5
B) r = 7
C) r = -8
D) r = 8

Answer 1

Using the slope formula and cross-multiplication, the missing coordinate r for the point (3, r) that lies on a line with slope 3/2 is found to be -20, which does not match any of the provided options. option (A)

Step-by-step explanation:

The student is asked to find the missing coordinate r for the point (3, r) that lies on the line with slope 3/2. To find r, one can use the slope formula which is (change in y)/(change in x). Our two points are (3, r) and (15, -2).

We have slope (m) = 3/2, so using the slope formula:

m = (y2 - y1) / (x2 - x1)

3/2 = (-2 - r) / (15 - 3)

Cross-multiply to get:

3/2 * 12 = -2 - r, which simplifies to 18 = -2 - r.

Adding 2 to both sides gives us 20 = -r, so r = -20.

This means that none of the options A through D is correct.