Step-by-step explanation:
y = f(x)
this has the same meaning. y is just the variable for the functional result value. while x is usually used as variable for the input value.
so (I recommend to use the brackets to make sure that people understand it is meant that x gets multilevel by 3 in the numerator, and not by 4 in the denominator),
y = 12 + (3/4)x
is the same as
f(x) = 12 + (3/4)x
you could also write it as
f(x) = 12 + 3x/4
don't skip things, always think about the rules of the sequence of the operations in an expression, and how a reader could understand it. always be as precise, complete and consistent as possible.
