Question

Find the equation of the line that passes through the points (1 , 2) and (5 , 3)

Answer 1

Line equation passing through the points is y-y1 = [(y2-y1)/(x2-x1)](x-x1)

Say the given points (x1,y1) = (1,2)

(x2,y2) = (5,3)

y-2 = [(3-2)/(5-1)]/(x-1)

y-2 = 1/4(x-1)

Cross multiplication.

4(y-2) = x-1

4y-8 = x-1

Add 8 to each side.

4y-8+8 = x-1+8

4y = x+7

Divide to each side by 4.

4y/4 = (x+7)/4

y = x/4+7/4