Help please Manuel ate of crakers on a plate. His brother ate of crackers. There were 5 crackers left on the plate. How many crackers were there, to begin with?

1/3 + 1/4 = 4/12 + 3/12 = 7/12
7/12 = both brothers ate 7 crackers out of 12 crackers

there were 5 crackers left on the plate means 5/12 crackers left on the plate

12 crackers at the begining

Looks pretty good to me!