Question 146476
p(x) = 5x^3 -3x^2+2x+7x^2

here there are two x^2 term, so combining 
 p(x) = 5x^3 +4x^2 +2x , since p(x) contains three terms , its a trinomial.

when we substitute x = 3 in p(X) , we get p(3)
 p(3) = 5(3)^3 + 4(3)^2  + 2 (3)
      = 5* 27 + 4 * 9 + 6 
     = 135 +36 +6
     = 177.