Final answer:
To find the missing coordinate r for a line with a slope of ⅓, we set up the equation based on the slope formula, (change in y) / (change in x), using the points (-1, -2) and (11, r). After cross-multiplying and simplifying the equation, we find that the missing coordinate r is 7.
Step-by-step explanation:
The student is asking how to find the missing coordinate r for the point (11, r) that lies on a line with a slope of ⅓.
To find this coordinate, we can use the formula for the slope of a line, which is (change in y) / (change in x) = slope. Here, we have the two points (-1, -2) and (11, r), and the slope is ¾.
First, we calculate the change in y, which is r - (-2) or r + 2, and the change in x, which is 11 - (-1) or 12. We can then set up the equation ¾ = (r + 2) / 12.
By cross-multiplying, we get 3×12 = 4(r + 2) which simplifies to 36 = 4r + 8. Subtracting 8 from both sides gives us 28 = 4r, and dividing by 4, we find that r = 7. Hence, the missing coordinate is 7.