Question

Find the value of x
when three points
(1,8) (5, 12) and (x, 28) lies on
straight line using slope
Plzzz answer this for assignment​

Answer 1

Given:

The three points  (1,8) (5, 12) and (x, 28) lies on  straight line

To find:

Find the value of x

Solution:

From given, we have,

The condition is,

If the points lie on a straight line then the area of the triangle formed by these points will be zero.

Hence by area of triangle formula, we get,

0 = 1/2 | x₁ (y₁ - y₂) + x₂ (y₂ - y₃) + x₃ ( y₃ - y₁) |

0 =  1 ( -4) + 5 ( -16) + x (20)

0 = | -4-80+20x |

84 = 20x

x = 4.2

Therefore, the value of x is 4.2