Three times Tara's age decreased by 2 years is the same as twice her age increased by 13 years. How old is
1 answer:
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Answer:
At approximately x = 0.08 and x = 3.92.
Step-by-step explanation:
The height of the ball is modeled by the function:
Where f(x) is the height after x seconds.
We want to determine the time(s) when the ball is 10 feet in the air.
Therefore, we will set the function equal to 10 and solve for x:
Subtracting 10 from both sides:
For simplicity, divide both sides by -1:
We will use the quadratic formula. In this case a = 16, b = -64, and c = 5. Therefore:
Substitute:
Evaluate:
Simplify the square root:
Therefore:
Simplify:
Approximate:
Therefore, the ball will reach a height of 10 feet at approximately x = 0.08 and x = 3.92.
Answer:
140
Step-by-step explanation:
To construct a subset of S with said property, we have two choices, include 3 in the subset or include four in the subset. These events are mutually exclusive because 3 and 4 can not both be elements of the subset.
First, let's count the number of subsets that contain the element 3.
Any of such subsets has five elements, but since 3 is already an element, we only have to select four elements to complete it. The four elements must be different from 3 and 4 (3 cannot be selected twice and the condition does not allow to select 4), so there are eight elements to select from. The number of ways of doing this is .
Now, let's count the number of subsets that contain the element 4.
4 is already an element thus we have to select other four elements . The four elements must be different from 3 and 4 (4 cannot be selected twice and the condition does not allow to select 3), so there are eight elements to select from, so this can be done in ways.
We conclude that there are 70+70=140 required subsets of S.