Check the picture below.
thus is at 0 = -16t² + 96t +640,

well, clearly it can't be a negative value for the elapsed seconds, so it can't be -4.
T=10.8, was the multiplication Symbol a part of the quest
To use the distributive property, we "distribute" a value on the outside of a set of parentheses to all of the values on the inside of the parentheses. For example...
6(3 + 9) = 6*3 + 6*9
For your problem, you only have one value 13.99, but we can split it apart to make it a little easier to work with (like with mental math). We can say that 13.99 is the same as 10 + 3.99. Now we can take it and multiply by 9 with the distributive property...
9(10 + 3.99) =
9*10 + 9*3.99 =
90 + 35.91 =
$125.91
Answer:
Rate of change = -0.2
Step-by-step explanation:
Given:
(-3, 3.6) and (5, 2)
Required:
Rate of change
Solution:
Formula for rate of change = change in y/change in x = 
Let,
(-3, 3.6) = (x_1, y_1)
(5, 2) = (x_2, y_2)
Plug in the values into the equation:
Rate of change = 
Rate of change =
= -0.2