Question

Determine the equation of the line with slope −2 that passes through the point M(−1, −3).

Answer 1

The slope formula: y = mx +b
m = -2, therefore we have: y = -2x + b
The line passes throught the point M(-1, -3) → x = -1, y = -3.
Substitute to the equation:
-3 = -2 · (-1) + b
-3 = 2 + b   |-2
b = -5
y = -2x - 5    |+2x
Answer: 2x + y = -5