write the equation of the line in slope - intercept form.

Explanation:

Step1: Identify the y - intercept

The line crosses the y - axis at the point $(0,4)$, so $b = 4$.

Step2: Calculate the slope

Pick two points on the line, say $(0,4)$ and $(2,0)$. The slope $m=\frac{y_2 - y_1}{x_2 - x_1}=\frac{0 - 4}{2-0}=\frac{-4}{2}=-2$.

Step3: Write the equation in slope - intercept form

The slope - intercept form is $y=mx + b$. Substituting $m=-2$ and $b = 4$ gives $y=-2x + 4$.

Answer:

$y=-2x + 4$