Is there an equation with the question? This doesn't mean anything^

as you notice above, is the first-row components from A, multiplying all the columns subsequently on B, and you add the products of that row, that gives you one component on the AB matrix
in the one above, we end up with a 2x3 AB matrix
Answer:
A book is worth $1 and a DVD is worth $12.
Step-by-step explanation:
The equations (2 unknowns and two equations, d is for a DVD and b is for a book):
For David: 3d+4b=40
For Anna: d+6b=18
Now multiply the second equation with -3 and add to the first equation:
3d+4b=40
−3d−18b=−54
Combined equation: −14b=−14 and b=1 (means that each book is worth $1).
Now for DVD price, use the second equation:
d=18−6 or d=12 (means that each DVD is worth $12).
A book is worth $1 and a DVD is worth $12.
Answer:
See the image for solution.
Brainlist please
Answer:
C) -212.5
Step-by-step explanation:
I've done this question on a quiz before.
Hope I helped!! :D