Luisa perez had a balance of $541.82 in her checking account on january 7, on january 10 she wrote a check to marty’s hair salon for $27.19, what is her new balance?

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?

If f(x)=3 over x+2 - square root x-3 then f(7)=

The coverage of a base station of a telecommunication company forms a disk with a radius of (kilometers). let be the distance of a cellphone from a base station. assume that the location of cellphones in use are randomly uniformly distributed within the disk. calculate the mean and variance for the random variable.