Question

What is the sum of the coefficients of the expression 3x4+5x2+x3x4+5x2+x?

Answer 1

 add like terms

 x^3x^4 = x^7

5x^2 + 5x^2 = 10x^2

you end up with x^7 +3x^4 + 10x^2 +x

Answer 2

The answer is 9.
The coefficients are 3,5, and 1 and when you add them up you get 9.