Hi- I am very confused. Can anyone lend me a hand?

Which expression shows the sum of the polynomials with like terms grouped together

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)

What ia the sum if the first 7 terms of the geometric series