To formulate the equation of a horizontal line passing through the point $(-3, 8)$, use the point-slope procedure.

Step 1 — Identify the slope and point: A horizontal line always has a slope of $0$, so $m = 0$. The given point is $(x_1, y_1) = (-3, 8)$.

Step 2 — Substitute into the point-slope form $y - y_1 = m(x - x_1)$: $y - 8 = 0(x - (-3))$

Step 3 — Simplify: Multiplying the right side by zero eliminates the expression: $y - 8 = 0$ $y = 8$

The final equation is $y = 8$, affirming that a horizontal line invariably takes the form $y = b$.