Jerome bought 15 videos from a department store. Some videos were new releases, x, which cost $19, and some videos were classics
, y, which cost $8. He spent a total of $164 on the videos. Which system of equations is set up correctly to model this information?
2 answers:
Answer:
The system of equations is
Step-by-step explanation:
Let
x------> the number of videos of new releases
y-----> the number of classics videos
we know that
------> equation A
------> equation B
Using a graphing tool
Solve the system of equations
Remember that the solution of the system of equations is the intersection point both graphs
The intersection point is
see the attached figure
therefore
the number of videos of new releases is
the number of classics videos is
You might be interested in
9514 1404 393
Answer:
they are not
Step-by-step explanation:
The inverse matrix is the transpose of the cofactor matrix, divided by the determinant.
The cofactor matrix for a 2×2 matrix is ...
The transpose of this will have the off-diagonal terms swapped, so the inverse matrix is ...
We see that the second matrix is the transpose of the cofactor matrix, but the determinant is (5)(2)-(3)(4) = -2, so there has clearly been no division by the determinant. The actual inverse matrix of the first one shown is ...
_____
You can compute the matrix product to see if you get an identity matrix. Here, the upper left term in the product is ...
(5)(2) +(4)(-3) = -2 . . . . . not 1, so the product matrix is not an identity matrix
The matrices are not inverses.