Marcus bought y movie posters for $3 each. Write an algebraic expression for total amount Marcus spent

3y would be an algebraic expression that represents what Marcus spent.

For example:

If he bought 12 posters then 3 (12) = 36 would represent the total amount he spent.

Well you would have to multiply 3 by what ever (y) is so if (y) was 5 then you could put the equation many ways but just some ways are

1) 3 (y) = 15

3 (5) = 15

15=15

2) 3*y=15

3*5=15

15=15

just two ways and remember what you do to one side you have to do to the other but in this case you leave the right side alone