So first of all b is a variable and this variable has a value of 5 so replace b with 5 and imagine there is a multiplication sign between the 3 and 5 (since they are not spaced out meaning you multiply) assuming you are using order of operations on this problem you would first find 5 (b) squared (muliplyed by the power of two) and multiply that answer (the answer of 5 squared) by 3 and then take the product of the answer you just got and subtract that from 5 (b)
Assuming you are not using order of operations you would first multiply 3 by 5 (b) and it would equal 15 then take 15 and multiply it by the power of 2 and then subract b Hope this helps you understand
