Answer:
7,000 is the answer
Step-by-step explanation:
Write a system of equation based on the number
For an instance, the two numbers are a and b.
"The sum of two numbers is 59" can be written as follows.
⇒ a + b = 59 <em>(first equation)
</em>"The difference is 15" can be written as follows.
⇒ a - b = 15 <em>(second equation)</em>
Solve the system of equation by elimination/substitution method.
First, eliminate b to find the value of a.
a + b = 59
a - b = 15
--------------- + (add)
2a = 74
a = 74/2
a = 37
Second, substitute 37 as a in one of the equations
a + b = 59
37 + b = 59
b = 59 - 37
b = 22
The numbers are 37 and 22
One dozen = 12
15/12 = 1.25
The cost of one fruit tart is $1.25
I guess no solution
4x +3 = 4X + 18
4X - 4X = 18 - 3
0 = 15
If A and B are equal:
Matrix A must be a diagonal matrix: FALSE.
We only know that A and B are equal, so they can both be non-diagonal matrices. Here's a counterexample:
![A=B=\left[\begin{array}{cc}1&2\\4&5\\7&8\end{array}\right]](https://tex.z-dn.net/?f=A%3DB%3D%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D1%262%5C%5C4%265%5C%5C7%268%5Cend%7Barray%7D%5Cright%5D)
Both matrices must be square: FALSE.
We only know that A and B are equal, so they can both be non-square matrices. The previous counterexample still works
Both matrices must be the same size: TRUE
If A and B are equal, they are literally the same matrix. So, in particular, they also share the size.
For any value of i, j; aij = bij: TRUE
Assuming that there was a small typo in the question, this is also true: two matrices are equal if the correspondent entries are the same.