Answer
The equation of the line in point slope form is
y - 13 = -2 (x - 4)
Simplifying this further
y - 13 = -2x + 8
y = -2x + 8 + 13
y = -2x + 21
Step-by-step explanation
The general form of the equation in point-slope form is
y - y₁ = m (x - x₁)
where
y = y-coordinate of a point on the line.
y₁ = This refers to the y-coordinate of a given point on the line
m = slope of the line.
x = x-coordinate of the point on the line whose y-coordinate is y.
x₁ = x-coordinate of the given point on the line
The coordinates of the points on the line are given in the form
f(x) = y
f(4) = 13 means (4, 13)
f(0) = 21 means (0, 21)
So, we need to calculate the slope of the line and use one of the points given as (x₁, y₁)
For a straight line, the slope of the line can be obtained when the coordinates of two points on the line are known. If the coordinates are (x₁, y₁) and (x₂, y₂), the slope is given as
(x₁, y₁) and (x₂, y₂) are (4, 13) and (0, 21)
x₁ = 4
y₁ = 13
x₂ = 0
y₂ = 21
m = -2
(x₁, y₁) = (4, 13)
x₁ = 4
y₁ = 13
y - y₁ = m (x - x₁)
y - 13 = -2 (x - 4)
Simplifying this further
y - 13 = -2x + 8
y = -2x + 8 + 13
y = -2x + 21
Hope this Helps!!!