Find the slope of the line and also write the equation of the line passing through the points A(- 3 , 4) and B (4 , 5).

Find the slope of the line and also write the equation of the line passing

through the points A(- 3 , 4) and B (4 , 5). 

Solution:

Since the line passes through the  point A(-3, 4) and B(4 , 5)

Slope = y2 – y1 = 5 – 4 = 1 x2 – x­1 4 + 3 7

Equation of the line by two point form

x – x1 = y – y1 x1 – x2 y1 – y2

x + 3 = y – 4 -3 – 4 4 – 5

x+3 = y – 4 -7  - 1

∴ -x – 3 = - 7y + 28

∴ - x + 7 y – 3 – 28 = 0

∴  - x + 7y – 31 = 0

Changing the sign,

x – 7y + 31 = 0