Question 684228
1. x^7-x^5= x^7-x^5 (different exponents cannot be subtracted). If you want to simplify: x^5(x^2-1) = x^5(x+1)(x-1). 


2. (14x^5)/(2x^7)= (14/2) * (x^5)/(x^7)= 7 * 1/(x^7-5)= 7 * 1/(x^2)= 7/x^2.