Is any value that is set and cannot change is variable?

1. during first 10 seconds 2. between 10 seconds and 35 seconds 3. during 35 seconds to 40 seconds

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

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