P(x, 4) and Q( 10, 8) are two points joined by a straight line in a plane. If the midpoint of the line is (9, 6), find the value of x.
A
12
B
9
C
8
D
7
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
midpoint(x) = \(\frac{x_1 + x_2}{2}\)
midpoint(y) = \(\frac{y_1 + y_2}{2}\)
Given (9, 6)
midpoint(x) = \(\frac{x + 10}{2}\) = 9
x + 10 = 2 x 9 = 18
x = 18 - 10 = 8.
Source: WAEC / JAMB / NECO Classroom Archive (Record #70256)