2cos^2xcos^2x simplified

Prove the divisibility of the following numbers: 25^9 + 5^7 is divisible by 30.also, read as (25 to the power of 9) + (5 to the power of 7) is divisible by 30. blank x 30what is the blank? ( it should be expressed in exponent form)

Let event a = you roll an even number on the first cube.let event b = you roll a 6 on the second cube.are the events independent or dependent? why?

Yvaries inversely as x. y =12 when x=5. find y when x=4