Answer:
If k = −1 then the system has no solutions.
If k = 2 then the system has infinitely many solutions.
The system cannot have unique solution.
Step-by-step explanation:
We have the following system of equations
The augmented matrix is
![\left[\begin{array}{cccc}1&-2&3&2\\1&1&1&k\\2&-1&4&k^2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%26-2%263%262%5C%5C1%261%261%26k%5C%5C2%26-1%264%26k%5E2%5Cend%7Barray%7D%5Cright%5D)
The reduction of this matrix to row-echelon form is outlined below.
![\left[\begin{array}{cccc}1&-2&3&2\\0&3&-2&k-2\\2&-1&4&k^2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%26-2%263%262%5C%5C0%263%26-2%26k-2%5C%5C2%26-1%264%26k%5E2%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{cccc}1&-2&3&2\\0&3&-2&k-2\\0&3&-2&k^2-4\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%26-2%263%262%5C%5C0%263%26-2%26k-2%5C%5C0%263%26-2%26k%5E2-4%5Cend%7Barray%7D%5Cright%5D)
![\left[\begin{array}{cccc}1&-2&3&2\\0&3&-2&k-2\\0&0&0&k^2-k-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccc%7D1%26-2%263%262%5C%5C0%263%26-2%26k-2%5C%5C0%260%260%26k%5E2-k-2%5Cend%7Barray%7D%5Cright%5D)
The last row determines, if there are solutions or not. To be consistent, we must have k such that
Case k = −1:
![\left[\begin{array}{ccc|c}1&-2&3&2\\0&3&-2&-1-2\\0&0&0&(-1)^2-(-1)-2\end{array}\right] \rightarrow \left[\begin{array}{ccc|c}1&-2&3&2\\0&3&-2&-3\\0&0&0&-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%26-2%263%262%5C%5C0%263%26-2%26-1-2%5C%5C0%260%260%26%28-1%29%5E2-%28-1%29-2%5Cend%7Barray%7D%5Cright%5D%20%5Crightarrow%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%26-2%263%262%5C%5C0%263%26-2%26-3%5C%5C0%260%260%26-2%5Cend%7Barray%7D%5Cright%5D)
If k = −1 then the last equation becomes 0 = −2 which is impossible.Therefore, the system has no solutions.
Case k = 2:
![\left[\begin{array}{ccc|c}1&-2&3&2\\0&3&-2&2-2\\0&0&0&(2)^2-(2)-2\end{array}\right] \rightarrow \left[\begin{array}{ccc|c}1&-2&3&2\\0&3&-2&0\\0&0&0&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%26-2%263%262%5C%5C0%263%26-2%262-2%5C%5C0%260%260%26%282%29%5E2-%282%29-2%5Cend%7Barray%7D%5Cright%5D%20%5Crightarrow%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Cc%7D1%26-2%263%262%5C%5C0%263%26-2%260%5C%5C0%260%260%260%5Cend%7Barray%7D%5Cright%5D)
This gives the infinite many solution.
Answer:
11
Step-by-step explanation:
ANSWER
EXPLANATION
The first equation is
The second equation is
We want to eliminate y, so we multiply the first equation by
We now subtract equation (3) from (2)
Multiply both sides by
Substitute into the first equation to solve for x .
Multiply to obtain
Multiply both sides by 2.
The solution is
The top box on the page explains the idea completely.
You need to read the top box several times, and understand it.
A ratio is a comparison of two quantities by division.
1). Days in May: 31
Days in a year: 365
Their ratio: 31/365 .
2). Sides of a triangle: 3
Sides of a square: 4
Their ratio: 3/4 .
The middle box explains how two ratios can be equal,
and it gives you a very detailed example. You should
read the middle box and understand it.
Ratios are fractions. They can be equal in just the same
way that any two fractions can be equal.
And you can simplify ratios in exactly the same way that
you simplify fractions ... divide top and bottom both by
the same number.
3). 8/12 Cook up three equal ratios.
1. divide top and bottom by 2 . . . . . 4/6
2. divide top and bottom by 4 . . . . . 2/3
3. multiply top and bottom by 9 . . . . 72/108
These are just some that I chose.
There are millions of others.
4). 20/25 Cook up three equal ratios.
1. divide top and bottom by 5 . . . . . 4/5
2. multiply top and bottom by 4 . . . . 80/100
3. multiply top and bottom by 3 . . . . 60/75
These are just some that I chose.
There are millions of others.
5). 5/6 Cook up three equal ratios.
1. multiply top and bottom by 2 . . . . 10/12
2. multiply top and bottom by 3 . . . .
3. multiply top and bottom by 9 . . . . 45/54
These are just some that I chose.
There are millions of others.
6). 10/14 Cook up three equal ratios.
1. divide top and bottom by 2 . . . . 5/7
2. multiply top and bottom by 2 . . . .
3. multiply top and bottom by (you choose) . . . .
