Is 4√x-3√x+4√x-8x+16 a polynomial

Me! last question, and i'm stuck! write the algebraic expression that models the word phrase. the product of 2 divided by the number h and 8 more than the number k

Find the perimeter of the triangle with vertices  d(3, 4),  e(8, 7), and  f(5, 9). do not round before calculating the perimeter. after calculating the perimeter, round your answer to the nearest tenth.  

Alex's monthly take home pay is $2,500. what is the maximum bad debt payment he can maintain without being in credit overload?