Question

10) Write the equation of the line passing through the points (-1, 2) and (3, 4)

A) y = 2x - 2
B) y - 2x - 10
9-x
D) y x -

Answer 1

Explanation:

(-1,2) = x1 , y1

(3,4) = x2 , y2

Using two points formula equation AB is :

( y - y1 ) = y2 - y1 / x2 - x1 ( x - x1 )

( y - 2 ) = 4 - 2 / 3 - ( -1 ) ( x - ( -1 )

y - 2 = 4 - 2 / 3 + 1 ( x + 1 )

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

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

y - 2 = ( x + 1 ) / 2

2( y- 2 )= ( x +1 )

2y - 4 = x + 1

- 4 - 1 = x - 2y

-5 = x - 2y

x - 2y +5 = 0 , which is the required equation..