Answer:
r = -8
Explanation:
Since we're given two points and the slope (m), we'll have to use the slope formula, which is
m = (y2 - y1) / (x2 - x1), where
- (x1, y1) is one point on the line
- and (x2, y2) is another point on the line
Step 1: Since we know that m = 2, we can allow (2, r) to be our (x1, y1) point and (5, -2) to be our (x2, y2) point. We can then solve for r:
2 = (-2 - r) / (5 - 2)
2 = (-2 - r) / 3
6 = -2 - r
8 = -r
-8 = r
Optional Step 2: We can check that r is the right coordinate by plugging it into the slope formula and seeing whether we get 2:
2 = (-2 - (-8)) / (5 - 2)
2 = (-2 + 8) / 3
2 = 6 / 3
2 = 2