Question

find an equation of the line that satisfies the given conditions. through (-1, 9), slope -3

Explanation:

Step1: Use point-slope form

The point-slope formula is $y - y_1 = m(x - x_1)$, where $(x_1, y_1)=(-1,9)$ and $m=-3$.
$y - 9 = -3(x - (-1))$

Step2: Simplify the equation

Simplify the right-hand side.
$y - 9 = -3(x + 1)$

Step3: Expand and solve for y

Distribute the slope and isolate y.
$y - 9 = -3x - 3$
$y = -3x - 3 + 9$
$y = -3x + 6$

Answer:

$y = -3x + 6$