This looks like a classic PEMDAS exercise.PEMDAS is the memory word to help you remember the ORDER in which to do different operations, when several different operations have to be done. It means . . .ParenthesesExponentsMultiplicationDivisionAdditionSubtraction .So we have to simplify 5³ + (10 - 5) - 40 .Lets go through PEMDAS one step at a time and do the operation as we come to each letter.ParenthesesThe quantity in parentheses is (10 - 5). That's 5 .Now the expression is 5³ + 5 - 40 .ExponentsThe term with an exponent is 5³. That's (5 · 5 · 5) = 125 .Now the expression is 125 + 5 - 40 .MultiplicationThere isn't any multiplication needed in our expression.DivisionThere isn't any division needed in our expression.AdditionThe addition in our expression is 125 + 5 . That's 130 .Now the expression is 130 - 40 .Subtraction .The subtraction in our expression is 130 - 40. That's 90 .And there we are.After it's been simplified, the whole expression is 90 .