The + arithmetic operator performs addition or indicates a positive numeric value.
num.exp + num.exp
Adds 1 to the variable, x.
x = x + 1
Adds the values in the variables price and tax and assigns the result to subtotal.
subtotal = price + tax
This is a complex arithmetic statement that first multiplies the unit.cost by qty and then adds the results to the variable called tax. The left and right parentheses are used to explicitly group precedence.
subtotal = tax + (unit.cost * qty)