We first find A2, for which we multiply A with itself. We perform matrix multiplication in which we multiply rows of first matrix with columns of second matrix element by element and add.
Answer:
-1
Step-by-step explanation:
Any variable without a visible coefficient means it has a coefficient of 1. Since it's negated, the coefficient is -1.
If there were only sandwiches bought, there would be 15, if there were only salads bought there would be 20. There’s probably more than one possibility, but that’s the best I can do, considering how long it’s been since I’ve done this type of problem. I’m all the way to learning determinants, so I really have to think to remember these. Sorry in advance if this doesn’t help at all, I’m not the best at this, but I can still try.
For a question like this, all you have to do is remember that a percentage is simply a fraction expressed as a decimal. So, all we have to do is:

, and then multiply our decimal answer by 100 to get the percentage:

= 0.34
0.34 x 100 = 34
Therefore 34% of the students walk to school.
I hope this helped and remember to please try and understand the maths that got the answer, not just writing the answer down :))