In the following Earliest Start Time (EST) graph, assume each unit of time is an hour.
How many hours will it take until Task F can be started?
14 hours
______________________________________
<em>
*100% CORRECT ANSWERS
</em>
<em>(SEE ATTACHMENTS)</em>
Answer:
![\left[\begin{array}{ccc}3&-1&\\-1&1/2\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D3%26-1%26%5C%5C-1%261%2F2%5C%5C%5Cend%7Barray%7D%5Cright%5D)
Step-by-step explanation:
The matrix system for the linear equations: x + 2y = 8, 2x + 6y = 9
![\left[\begin{array}{ccc}1&2&\\2&6\\\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}8\\9\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%262%26%5C%5C2%266%5C%5C%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D8%5C%5C9%5Cend%7Barray%7D%5Cright%5D)
To get the coefficient of x and y, the inverse of the first matrix (let the first matrix be A) must be known.
= (1 / determinant of A) x Adjoint of A
the determinant of A = (1 x 6) - (2 x 2) = 6 - 4 = 2
Adjoint of A = ![\left[\begin{array}{ccc}6&-2&\\-2&1\\\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D6%26-2%26%5C%5C-2%261%5C%5C%5Cend%7Barray%7D%5Cright%5D)
= ![\frac{1}{2} \left[\begin{array}{ccc}6&-2\\-2&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D6%26-2%5C%5C-2%261%5Cend%7Barray%7D%5Cright%5D)
=
If two fractions have the same denominator, that means the total number of parts is the same. For example, you have two batches of cookies, which each have 8 cookies.
But the numerator tells you the number of parts you are dealing with. Going back to our cookie example, say you ate 3 cookies and your little brother only had 1. If you ate 3 cookies, you ate 3/8 of the cookies. Your little brother ate 1/8 of the cookies.
So, which one is the greatest fraction? In this case, who had more cookies? That would be you. So, the greater numerator means a greater fraction.
Answer: the fraction with the greater numerator
