Can anyone me with this problem? i got my answer incorrect, and i don’t understand why.

On a piece of paper graph f(x)=5•(0.4)^x

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

How many solutions does the nonlinear system of equations graphed bellow have?