LMAO I remember the boys in my class kept asking the teacher to let us do algebra😭
BTW I think it's like when they(the question) don't tell a letter is a certain number that means it's a letter that you shouldn't add up with a different letter(like 2a+2a+3b=4a+3b cuz you can't add up the 'a' numbers with the 'b' numbers since they are different letters). And when they do tell a letter is a certain number(like they say a=3) means if it's next to a number you have to make a product out of them(like 5a is supposed to be 5x3 which is 15) and if it's just alone between the -/+/x/÷ then it's just itself

(I'm not completely sure if I'm right 😭 ig I've only learnt the basic skills of it)