Sarah is walking diagonally across a park as modeled by the equation y = x − 1. Suppose Marcus starts walking at the point (0, 9) so his path is perpendicular to Sarah's. At what point will Sarah's path and Marcus's path intersect?

Step-by-step explanation:

Consider the attached figure.

The equation is

At

At

Plot points .

Marcus starts walking at the point B(0, 9) so that his path is perpendicular to Sarah's at point A.

From the graph, Sarah's path and Marcus's path intersect at point

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form