My math problem

This is my work from this word problem.I am only allowed to use 5 and 7 to get to 38.I used pluses and I + 7 with 7 that makes 14 and then I + 14 and 7 that makes 21 then I +7 with 21 that makes 28 then I + 5 and 5 that makes 38 but times tables were the fastest way because you just need to 7 x 4 =21 7x1=28 5x2=38