5, Write an equation of the line that passes through the points (1, 1) and (7, 4).

A. y = 2x - 10
B. y = 2x - 1
C. y = (½)x + 5
D. y = (½)x + (½)

Answer :

Slope = (y2 - y1) / (x2 - x1) = (4 - 1) / (7 - 1) = 3 / 6 = 1/2

Hence, y = (1/2)x + c
As point (1,1) passes through this line, 1 = (1/2)*1 + c
c = 1/2

As such, the answer is (d) y = (1/2)x + (1/2)