Is 3x^2-5x^4+2x-12 a polynomial

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

Afarm that has 4 x 10^2 acres has 1.2 x 10^5 cattle. what is the average number of cattle per acre? write the answer in scientific notation. answere asap

Suppose your school costs for this term were $4900 and financial aid covered 3/4 of that amount. how much did financial aid cover? and how much do you still have to pay?