I believe your answer is 6 seconds.
Because the height of the ball = -16(x² - 5x - 6), when the height of the ball is 0, which is when it is on the ground, we can set -16(x² - 5x - 6) equal to 0. This also allows us to divide by -16, and then we can solve the equation:
x² - 5x - 6 = 0
(x - 6)(x + 1) = 0
So x = 6 or x = -1, and because a quantity of time cannot be negative, x would have to be 6, which means it takes 6 seconds for the ball to reach 0 feet.
I hope this helps!
First, distribute the minus sign across the second set. So you have:
x - y + 1 - x - y + 1
Now, we combine like terms:
x-x=0
-y-y=-2y
1+1=2
So we have -2y+2
Hope that helps.
If she maintains her average amount of movies bought every week, then she will buy 20 DVDs in 10 weeks. Explanation: she buys 4 every week, so if we want to find out how many are in 10 weeks, we must multiply two until we get to 10 ( five weeks ) then multiply that buy her average of movies. And that is how we get the answer of 20 DVDs! ( her at least I did )
Anyways, hope this helps!
