How to do question 24. a and b?

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1 Answer
Feb 3, 2018

a) Equation of BC is color(blue)(3y - x = 22)

b) Coordinates of color(green)(C (14, 12)

Explanation:

A (4,2), B (2,8)

Equation of AC color(blue)(y = x - 2)

a) To find equation of BC#

Slope of AB = (8-2) / (2 - 4) = -3#

Slope of BC = -1 / (-3) = 1/3#

Equation of BC

y - 8 = (1/3) (x - 2)

3y - 24 = x - 2

Equation of BC is color(blue)(3y - x = 22)

b) To find the coordinates of C.

This can be arrived at by solving equations of AC and BC.

Equation of AC y - x = -2 Eqn (1)

Equation of BC 3y - x = 22 Eqn (2)

Subtracting Eqn (1) from (2),

3y - y = 22 - (-2)

y = 24 / 2 = 12

Substituting value of y in equation (1),

12 - x = -2

x = 12 + 2 = 14

Coordinates of color(green)(C (14, 12)