If you were to correctly simplify this equation, the answer would be a negative.
The answer is: n = -5
Here's how I got my answer:
Step 1: Add 3 to both sides. Which leaves us with 
Step 2: Simplify
to 45. Which leaves us with 
Step 3: Divide both sides by -9. Which leaves us with 
Step 4: Simplify
, to get your answer, n = -5.
90 can be written as 450/5 plus the 1/5. Together, it can be written as 451/5.
Answer:
81.2 feet (nearest tenth)
Step-by-step explanation:
Hello!
10 seconds to return to the ground.
7 seconds to reach 576 feet above the ground.
Find the amount of time taken to reach the ground by setting the equation equal to 0:
0 = -16t² + 80t + 800
Factor out -16 from the equation:
0 = -16(t² - 5t - 50)
Factor the terms inside of the parenthesis:
0 = -16(t - 10)(t + 5)
Find the zeros:
t - 10 = 0
t = 10
t + 5 = 0
t = -5
Time can only be positive in this instance, so the correct answer is 10 sec.
Find the time by substituting in 576 for the height:
576 = -16t² + 80t + 800
Subtract 800 from both sides:
-224 = -16t² + 80t
Rearrange:
0 = -16t² + 80t + 224
Simplify:
0 = -16(t² - 5t - 14)
0 = -16(t - 7)(t + 2)
t = 7 seconds.
You have to add and divide for the mean(average) so add all of them up and then divide by 3 :)