The gradient of the line passing through the points P(4, 5) and Q(x, 9) is (frac{1}{2}). Find the value of x.
-
A.
-4 -
B.
0 -
C.
4 -
D.
12
Correct Answer: Option D
Explanation
(Gradient = frac{y_{1} – y_{2}}{x_{1} – x_{2}} )
(frac{1}{2} = frac{5 – 9}{4 – x})
(frac{1}{2} = frac{-4}{4 – x} implies -8 = 4 – x)
(x = 4 + 8 = 12)