She spent $75
The best news of this problem is that the books all cost the same.
So 8 + 3 + 4 = 15 books total
15 x $5 = $75
Answer:
See attachment
Step-by-step explanation:
The given matrix equation is:

To find Matrix X, we need to multiply both sides of the equation by 2 to obtain:

This simplifies to;

By scalar multiplication, we multiply each entry in the matrix A by to 2 to obtain matrix X.
Answer:
-4.32 would be the answer
i hope this helps you