What number will you add to - 6x to get an answer of zero? That is, what is the Additive Inverse of - 6x?

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

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !

Twice the sum of a number and 2 is equal to three times the difference of the number and 8. find the number.