I need to finish 3 or 4 problems like this tonight,

0.4x + 0.1y = 0.28

x+y=25

also

"Medication A is given every 4 hours and Medication B is given twice each day. The total intake of the 2 meds is restricted to 50.6mg per day for a patient. If the ratio of the dosage of A to B is 5 to 8, find the dosage for each administration for each medication."

so I know the one equation is

6x+2y=50.6

I don't know how to do the other one...

thanks!