Answer:
174
Step-by-step explanation:
You should look at the mean and do this:
5*28 so now you know all the ages which is 140 now you do 140/29 and you get 4.8....... so you can see that the answer is 174
The row echelon form of the matrix is presented as follows;
![\begin{bmatrix}1 &-2 &-5 \\ 0& 1 & -7\\ 0&0 &1 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D1%20%26-2%20%20%26-5%20%20%5C%5C%200%26%201%20%26%20%20-7%5C%5C%200%260%20%20%261%20%20%5C%5C%5Cend%7Bbmatrix%7D)
<h3>What is the row echelon form of a matrix?</h3>
The row echelon form of a matrix has the rows consisting entirely of zeros at the bottom, and the first entry of a row that is not entirely zero is a one.
The given matrix is presented as follows;
![\begin{bmatrix}-3 &6 &15 \\ 2& -6 & 4\\ 1&0 &-1 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D-3%20%266%20%20%2615%20%20%5C%5C%202%26%20-6%20%26%20%204%5C%5C%201%260%20%20%26-1%20%20%5C%5C%5Cend%7Bbmatrix%7D)
The conditions of a matrix in the row echelon form are as follows;
- There are row having nonzero entries above the zero rows.
- The first nonzero entry in a nonzero row is a one.
- The location of the leading one in a nonzero row is to the left of the leading one in the next lower rows.
Dividing Row 1 by -3 gives:
![\begin{bmatrix}1 &-2 &-5 \\ 2& -6 & 4\\ 1&0 &-1 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D1%20%26-2%20%20%26-5%20%20%5C%5C%202%26%20-6%20%26%20%204%5C%5C%201%260%20%20%26-1%20%20%5C%5C%5Cend%7Bbmatrix%7D)
Multiplying Row 1 by 2 and subtracting the result from Row 2 gives;
![\begin{bmatrix}1 &-2 &-5 \\ 0& -2 & 14\\ 1&0 &-1 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D1%20%26-2%20%20%26-5%20%20%5C%5C%200%26%20-2%20%26%20%2014%5C%5C%201%260%20%20%26-1%20%20%5C%5C%5Cend%7Bbmatrix%7D)
Subtracting Row 1 from Row 3 gives;
![\begin{bmatrix}1 &-2 &-5 \\ 0& -2 & 14\\ 0&2 &4 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D1%20%26-2%20%20%26-5%20%20%5C%5C%200%26%20-2%20%26%20%2014%5C%5C%200%262%20%20%264%20%20%5C%5C%5Cend%7Bbmatrix%7D)
Adding Row 2 to Row 3 gives;
![\begin{bmatrix}1 &-2 &-5 \\ 0& -2 & 14\\ 0&0 &18 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D1%20%26-2%20%20%26-5%20%20%5C%5C%200%26%20-2%20%26%20%2014%5C%5C%200%260%20%20%2618%20%20%5C%5C%5Cend%7Bbmatrix%7D)
Dividing Row 2 by -2, and Row 3 by 18 gives;
![\begin{bmatrix}1 &-2 &-5 \\ 0& 1 & -7\\ 0&0 &1 \\\end{bmatrix}](https://tex.z-dn.net/?f=%5Cbegin%7Bbmatrix%7D1%20%26-2%20%20%26-5%20%20%5C%5C%200%26%201%20%26%20%20-7%5C%5C%200%260%20%20%261%20%20%5C%5C%5Cend%7Bbmatrix%7D)
The above matrix is in the row echelon form
Learn more about the row echelon form here:
brainly.com/question/14721322
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Answer:
Part 1) The number of cups of flour needed to make 4 pizzas is 26
Part 2) The number of pizzas Luigi can make with 13 cups of flour is 2
Step-by-step explanation:
we know that
Luigi uses 39 cups of flour for every 6 pizzas he makes
Let
y ----> the number of cups of flour used
x ---> the number of pizzas he makes
In this problem
The relationship between the variables x, and y, represent a proportional variation
we have the ordered pair (6,39)
so
![\frac{y}{x}=\frac{39}{6}](https://tex.z-dn.net/?f=%5Cfrac%7By%7D%7Bx%7D%3D%5Cfrac%7B39%7D%7B6%7D)
Part 1) Find out the number of cups of flour needed to make 4 pizzas
using a proportion
![\frac{y}{4}\ \frac{cups\ of\ flour}{pizzas}=\frac{39}{6}\ \frac{cups\ of\ flour}{pizzas}](https://tex.z-dn.net/?f=%5Cfrac%7By%7D%7B4%7D%5C%20%5Cfrac%7Bcups%5C%20of%5C%20flour%7D%7Bpizzas%7D%3D%5Cfrac%7B39%7D%7B6%7D%5C%20%5Cfrac%7Bcups%5C%20of%5C%20flour%7D%7Bpizzas%7D)
Solve for y
![y=\frac{39}{6}(4)](https://tex.z-dn.net/?f=y%3D%5Cfrac%7B39%7D%7B6%7D%284%29)
![y=26\ cups\ of\ flour](https://tex.z-dn.net/?f=y%3D26%5C%20cups%5C%20of%5C%20flour)
Part 2) Find out the number of pizzas Luigi can make with 13 cups of flour
using a proportion
![\frac{13}{x}\ \frac{cups\ of\ flour}{pizzas}=\frac{39}{6}\ \frac{cups\ of\ flour}{pizzas}](https://tex.z-dn.net/?f=%5Cfrac%7B13%7D%7Bx%7D%5C%20%5Cfrac%7Bcups%5C%20of%5C%20flour%7D%7Bpizzas%7D%3D%5Cfrac%7B39%7D%7B6%7D%5C%20%5Cfrac%7Bcups%5C%20of%5C%20flour%7D%7Bpizzas%7D)
Solve for x
![x=13(6)/39](https://tex.z-dn.net/?f=x%3D13%286%29%2F39)
![x=2\ pizzas](https://tex.z-dn.net/?f=x%3D2%5C%20pizzas)
Answer: $ 568.99
Because 18.99+22 x 225/9 = 568.99
Yes that’s completely true because of course you can’t say it is false