Answer:
x=-1/85; y=-283/85; z=2/17
Step-by-step explanation:
Using an algebraic method like elimination or substitution would take a lot of steps which could lead to mistake the calculations. In this case, I decided to use the Gaussian elimination. We can express the system in matrix form as follows:
![\left[\begin{array}{ccc}2&-4&6\\9&-3&1\\5&0&9\end{array}\right] \left[\begin{array}{ccc}x\\y\\z\end{array}\right] =\left[\begin{array}{ccc}14\\10\\1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D2%26-4%266%5C%5C9%26-3%261%5C%5C5%260%269%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5C%5Cz%5Cend%7Barray%7D%5Cright%5D%20%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D14%5C%5C10%5C%5C1%5Cend%7Barray%7D%5Cright%5D)
To begin the calculations, we write the system in augmented matrix form and use the Gaussian elimination:
![\left[\begin{array}{ccccc}2&-4&6&|&14\\9&-3&1&|&10\\5&0&9&|&1\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccccc%7D2%26-4%266%26%7C%2614%5C%5C9%26-3%261%26%7C%2610%5C%5C5%260%269%26%7C%261%5Cend%7Barray%7D%5Cright%5D)
By applying the Gaussian elimination, the final matrix is the following:
![\left[\begin{array}{ccccc}1&0&0&|&-1/85\\0&1&0&|&-283/85\\0&0&1&|&2/17\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccccc%7D1%260%260%26%7C%26-1%2F85%5C%5C0%261%260%26%7C%26-283%2F85%5C%5C0%260%261%26%7C%262%2F17%5Cend%7Barray%7D%5Cright%5D)
In order to verify the results, it´s enough to substitute the calculated values in the original equations to see if the equalities are correct. Here you can see the verification for all of the equations:
A
180 - S = R
180 - 65 = 115
The answer would be 1.5 because you add .75 +.75 to get the answer
The U.S RDA for protein is 46g for girl
If a piece of fried chicken contains 23g
To find the pieces of chicken she is to eat to satisfy the U.S RDA requirement,
The number of pieces of chicken is
The number of pieces of chicken is
Hence, the right option is B
Answer:
none of the above
Step-by-step explanation:
The grocer's revenue will be the product of the number of loaves sold (30-2x) and their price (2.50+0.50x).
Revenue will be positive for values of x between those that make these factors be zero. The number of loaves sold will be zero when ...
... 30 -2x = 0
... 15 -x = 0 . . . . . divide by 2
... x = 15 . . . . . . . add x
The price of each loaf will be zero when ...
... 2.50 +0.50x = 0
... 5 + x = 0 . . . . . . . multiply by 2
... x = -5 . . . . . . . . . . subtract 5
Revenue will be positive for any number of increases greater than -5 and less than 15.
_____
D is the best of the offered choices, but it is incorrect in detail. -5 is a number less than 15, but will give zero revenue.
