Answer :

tjmk00
7x^2 put them both on one side then u have 7x^2 - 175 = 0 then u factor it and u get 7(x^2 - 25) = 0
7x^2=175 
subtract 175 from both sides
7x^2-175=0
then factor out 7
7(x^2-25)
so now it would be easy to figure out that 
(x^2-25)=(x+5)(x-5)
so now the answer is
7(x-5)(x+5)