Answer:
$7
Step-by-step explanation:
Your two equations are ...
Double the second equation and subtract the first:
2(2s +4t) -(4s +6t) = 2(42) -(70)
2t = 14 . . . . . simplify
t = 7 . . . . . . . divide by 2
The cost of each tie is $7.
Answer: -13
Step-by-step explanation:
c-2y
= -5-2(4)
= -5 - 8
= -13
Answer:
C. True; by the Invertible Matrix Theorem if the equation Ax=0 has only the trivial solution, then the matrix is invertible. Thus, A must also be row equivalent to the n x n identity matrix.
Step-by-step explanation:
The Invertible matrix Theorem is a Theorem which gives a list of equivalent conditions for an n X n matrix to have an inverse. For the sake of this question, we would look at only the conditions needed to answer the question.
- There is an n×n matrix C such that CA=
. - There is an n×n matrix D such that AD=
. - The equation Ax=0 has only the trivial solution x=0.
- A is row-equivalent to the n×n identity matrix
. - For each column vector b in
, the equation Ax=b has a unique solution. - The columns of A span
.
Therefore the statement:
If there is an n X n matrix D such that AD=I, then there is also an n X n matrix C such that CA = I is true by the conditions for invertibility of matrix:
- The equation Ax=0 has only the trivial solution x=0.
- A is row-equivalent to the n×n identity matrix
.
The correct option is C.
Answer:
25.4
Step-by-step explanation:
If double of the number 'x' is 50.8, (2x=50.8)
Then the original number must be half of that value, (x=50.8/2)
50.8/2 = 25.4