Answer: Hold on
Step-by-step explanation: LEt me see this is tricky
Answer:

Step-by-step explanation:
We know that the equation that models the height of the ball as a function of time is
.
Where the initial speed is 80 feet.
When the ball lands on the ground, its height will be
.
So to know how long it will take the ball to reach the ground, equal h (t) to zero and solve for t.

To solve this quadratic equation we use the quadratic formula.
For an equation of the form:

The quadratic formula is:

In this case

Then


We take the positive solution

(10-5r)^2=(10-5r)(10-5r) or
25r^2-100r+100
divide the whole thing by 5 and get
5(5r^2-20r+20)
divide the whole thing by 5 again
25(r^2-4r+4)
factor by finding what two numbers add to get -4 and multiply to get 4 (-2 and -2 work)
r^2-4r+4=(r-2)(r-2) or 25((r-2)^2)
Answer:
10 weeks
Step-by-step explanation:
Use the equation 180+17w=350
In order to check a solution, just plug in the coordinates. The 1 is x, and the -1 is the y. Just plug the numbers in and see if it works out:
y = 3x + 2
(-1) = 3(1) + 2
-1 = 5
-1 is NOT equal to 5, so (1, -1) is NOT a solution of y = 3x + 2.