What is the difference? ​

What is the size of the matrix resulting from

The verbal translation for the difference of m and 7 increased by 15

The dolphins at the webster are fed 1/2 of a bucket of fish each day the sea otters are fed 1/2 as much fish as the dolphins how many buckets of fish are the sea fed each day? simplify you answer and write it as a proper fraction or as a whole or mixed number