Prove that the function: y(x) = a cosx + b sin x(a and b are constants), is a solution to the differential equation.

Which is greater, 7 p 5 or 7 c 5? 7p5 7c5

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?