Answer:
The answer is that r = 7/6
Explanation:
Given point: (7, 5)
Given slope: m = 6
Use the point slope form of the equation:
y - y1 = m(x - x1)
y - 5 = 6(x - 7)
y - 5 = 6x - 7
y = 6x + 2
Now, find r for the point (r, 9) by substitution:
9 = 6x + 2
6x + 2 = 9
6x = 7
x = 7/6
Proof:
y = 6x + 2
f(x) = 6x + 2
f(7/6) = 6(7/6) + 2
= 42/6 + 2
= 7 + 2 = 9, giving (7/6, 9). r = 7/6
Hope this helps! Have a great day!