Help plss must be right answer be this is a test

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)

In a sale there is 25% of all prices a chair costs £45 in sale how much was it before the sale

Given: prst square pmkd is a square pr = a, pd = a find the area of pmct.