A line passes through the origin and the point ((1frac{1}{4}, 2frac{1}{2})). Find the y-coordinate of the line when x = 4.
-
A.
2 -
B.
4 -
C.
6 -
D.
8
Correct Answer: Option D
Explanation
The gradient of the equation = (frac{y_{1} – y_{0}}{x_{1} – x_{0}} = frac{frac{5}{2} – 0}{frac{5}{4} – 0})
= (frac{frac{5}{2}}{frac{5}{4}} = 2)
The line passes through the origin, therefore the equation of the line is y = mx
(y = 2x)
When x = 4, y = 2 x 4 = 8.