Answer:
-22
Step-by-step explanation:
You can start with the form
∆y(x -x1) -∆x(y -y1) = 0
Here, we have
∆y = 11-(-3) = 14
∆x = -3-1 = -4
and we can choose (x1, y1) = (1, -3). This gives
14(x -1) -(-4)(y -(-3)) = 0
14x +4y -2 = 0
All these terms have a common factor of 2 that we can remove. Adding 1 to the result puts it in standard form:
7x +2y = 1
Average speed = 24 3/4 / 1 1/2 = 99/4 / 3/2 = 99/4 x 2/3 = 16 1/2 miles per hour.
Answer:
40 minutes
Step-by-step explanation:
Let c represent the number of minutes it would take colleen to finish the job when he is working alone. Hence, it can be represented by the equation:

Solving the quadratic equation to get c gives:
c = -12 and c = 40
Since the time cannot be negative, hence c = 40 minutes.
It would take colleen 40 minutes to clear the yard of leaves alone