The gradient of a line joining (x,4) and (1,2) is (frac{1}{2}). Find the value of x

A.
5 
B.
3 
C.
3 
D.
5
Correct Answer: Option A
Explanation
(text{Gradient m} = frac{y_2 – y_1}{x_2 – x_1})
(frac{1}{2} = frac{2 – 4}{1 – x})
1 – x = 2(2 – 4)
1 – x = 4 – 8
1 – x = 4
x = 4 – 1
x = 5
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