My son ran into this on a standardized test. I have taken lots of math, but the notation is new to me. The question reads,

if a (psi) b = a^2 -2b , which yields the largest value?

a) 3 (psi) 4

b) 3 (psi) 5

c) 4 (psi) 2

d) 5 (psi) 7

From this it's clear that only the expression to the right of the = can be evaluated, because none of the values provided are equal if you treat it as an equation where b = a^2 - 2b

So my guess is that somebody just wanted to use a fancy greek letter, when it would have been simpler to say c = a^2 - 2b so which (a,b) pair yields the largest c?