Hi there!
We can create an equation for the line PR using the given coordinates. Use the following formula for the slope:
Plug in the coordinates for P and R:
Find the equation by using point-slope form:
y - y1 = m(x - x1)
Plug in a coordinate and the slope:
y - (-5) = -4/3(x - ( - 1))
Simplify:
y + 5 = -4/3(x + 1)
To find the y-coordinate if x = 2, plug in the x value:
y + 5 = -4/3(2 + 1)
y + 5 = -4/3(3)
y + 5 = -4
y = -9
Thus, the coordinate is (2, -9)