Question 474634
Steps are: parentheses, exponents, and other composite functions take precedence over other operations, followed by multiplication/division, followed by addition/subtraction (hence, PEMDAS). It is important so that mathematicians have a clear way of defining each equation, e.g. if 5 x 3 + 7 and 5 x (3 + 7) were both done left to right, then there would be no easy way to define 5 x (3 + 7) (except maybe (3 + 7) x 5) but we don't want to do that for a complicated problem.



I say "other composite functions" because exponents are not the only one (here I will use a factorial as an example of a composite function). Suppose we want to evaluate


*[tex \LARGE 5(2^{3+1} + 4) + (2+2)! - 3]


We can still go from left to right, but follow the order of operations. 2^(3+1) is the same as 2^4, or 16. 16 + 4 = 20, 20 times 5 is 100.



Next, we have 2+2 is 4. The exclamation point denotes an operation called a factorial (something you'll learn in combinatorics), in which the factorial of a positive integer is simply the product of it and all other positive integers less than it. So 4! = 4*3*2*1 = 24. 100 + 24 = 124.


We subtract 3, 124 - 3 = 121 to get our final answer.