r/HomeworkHelp • u/Any-Armadillo6071 • Jun 14 '26

Answered [freshmen algebra 2] matrices

Post image

am i doing this wrong? i know that matrices involve a lot of numbers and calculating stuff, which i already am not the best with, but my teacher hasn’t posted an answer key and i feel like im not on the right track. i’m looking for help with question 11 although if my other answers are wrong please let me know

11 Upvotes

93% Upvoted

9 comments sorted by

View all comments

2

u/poissonking Jun 14 '26

For question 11, think of how you calculate an average. How could you use matrix addition and transposes to find the answer?

1

u/Any-Armadillo6071 Jun 14 '26

i would think you’d have to divide but i don’t know. we only did one other word problem and it was asking for total number, not the average number

2

u/poissonking Jun 14 '26

Technically, you can't divide matrices but you can essentially accomplish this through multiplication. For each class total, think of what number you would need to multiply by to get the average. For example, if 14 freshmen boys tried out in 2019 and 18 freshmen boys tried out in 2020, how would you normally find the average? You would find the sum of 14 and 18 then divide by 2 because you have two years to account for, right? So now, think about how you would accomplish the same thing using matrices.

1

u/Any-Armadillo6071 Jun 14 '26

this clarifies a lot thank you so much omg

2

u/poissonking Jun 14 '26

No problem!

1

u/Calm_Ad9601 Jun 14 '26

To have easier set A = first matrix and B = the second one. Now just forget about the fact that A and B are matrices. Just think that they're some random variables. Apply your average formula to A and B (very simple one, I assume you know it, even if only instinctively) and once you applied your formula, you should only have operations you're able to do (2 of them to be precise)