Cost of each bags of flour = $2.50
Cost of each bags of butter = $3.75
Solution:
Let f be the bags of flour and b be the pounds of butter.
Cost of 20 bags of flour 16 pound of butter = 110
⇒ 20f + 16b = 110 -------------------- (1)
Cost of 30 bags of flour 12 pound of butter = 120
⇒ 30f + 12b = 120 -------------------- (2)
Equation (1) and (2) are the system of equations.
(2) ⇒ 30f + 12b = 120
Subtract 30f from both sides.
⇒ 12b = 120 – 30f
Divide by 12 on both sides.
-------------------- (3)
Substitute (3) in (1).
Subtract 160 from both sides.
Divide by –20, we get
f = 2.50
Substitute f = 2.5 in equation (3), we get
b = 3.75
Cost of each bags of flour = $2.50
Cost of each bags of butter = $3.75
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:
6.86
Step-by-step explanation:
I think it’s 8 ( I’m not sure )
