Question

Line AB passes through points A(–6, 6) and B(12, 3). If the equation of the line is written in slope-intercept form, y = mx + b, then m =1/6 – and b = .

Answer 1

Let the straight line have the equation y = mx + b

The line passes through A (-6,6), therefore
-6m + b = 6 (1)

The line passes through B (12.3), therefore
12m + b = 3 (2)

Subtract (2) from (1).
-6m + b - (12m + b) = 6 - 3
-18m = 3
m = -1/6

From (2), obtain
12*(-1/6) + b = 3
- 2 + b = 3
b = 5

Answer: m = -1/6, b = 5