Which expressions are polynomials?

Can someone please check my work?

Part of the total score for each program is the sum of five program component scores. on the free program, the sum of these five program component scores is multiplied by a factor of 2.0. yuzuru hanyu, of japan, earned scores of 9.07, 8.96, 8.89, 9.21, and 9.36 for the program components portion of his free program. how many total points did he receive for this portion?

Which expressions are equivalent to -6 + 3m

If the scale factor between two circles is 2x/5y what is the ratio of their areas?