Answer:
50, percentage decreased by 60% (percent) of its value = 20
Step-by-step explanation:
Answer: h = 9
Step-by-step explanation: A system of linear equations is consistent when it has at least one solution.
The matrix given is:
![\left[\begin{array}{ccc}-15&21&h\\5&-7&-3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-15%2621%26h%5C%5C5%26-7%26-3%5Cend%7Barray%7D%5Cright%5D)
Transform this matrix in a row-echelon form:
![\left[\begin{array}{ccc}-15&21&h\\0&0&-9+h\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D-15%2621%26h%5C%5C0%260%26-9%2Bh%5Cend%7Barray%7D%5Cright%5D)
For this row-echelon form to have solutions:
-9 + h = 0
h = 9
For this system to be consistent: h = 9.
Answer:
If pi is used as pi 113.1
or
If 3.14 is used as pi 113.04
Step-by-step explanation:
A = pi(r)²
The answer to that question is the sum of the hours he studied for on both days, which will be 1/4 + 3/8.
However, we cannot add fractions with different denominators. In this case, it's 4 and 8.
So if we want to add them, we must make the denominators similar to each other. How to make 4 into 8? We multiply it by 2: 4 x 2 = 8.
BUT when we multiply fractions, we must multiply both the numerator and the denominator by the same number to keep its original value. In this case, if you want to multiply 4 by 2, you must also multiply 1 by 2.
=> SO to make 1/4 into y/8, we will multiply it like this (1 x 2) / (4 x 2) = 2/8
Now we can add the 2 fractions together. 2/8 + 3/8 = (2 + 3)/8 = 5/8. THIS IS YOUR ANSWER.
TL;DR: He studied 5/8 (or 0.625) hour altogether on both days.
