Question

The points -1, -9, and 7, r lie on a line with a slope of 5/4. Find the missing coordinate, r.

A) 11
B) 16
C) 14
D) 12

Answer 1

To find the missing coordinate, substitute the given values into the formula for slope, simplify the equation, and solve for the missing coordinate. The missing coordinate, r, is -19.

Step-by-step explanation:

To find the missing coordinate, we can use the formula for slope:
slope = (change in y-coordinates)/(change in x-coordinates)

Given two points (-1, -9) and (7, ?) on the line with a slope of 5/4, we can substitute these values into the formula:
(-9 - ?)/(7 - (-1)) = 5/4

Simplifying and solving for ?, we get:
-9 - ? = (5/4)(7 - (-1))
-9 - ? = (5/4)(8)
-9 - ? = 10

Now, we can solve for ?, by moving -9 to the right side of the equation:
? = -9 - 10
? = -19

Therefore, the missing coordinate, r, is -19. The correct answer is option C) -19.