To get this answer, you would do the order of operations. Do the parenthesis first, exponents, multiply/divide, and add/subtract. Do 5-3 then bring down the power down which is two. 2 to the power of 2 is 4. Then do 7-3 which is 4. Bring down the rest of the problem. Now multiply 3x7 and divide 4 into 4. And the last step is to simply add the rest of the numbers which is 5+21+1. The answer is 27. Hope this helps :)