Frank thinks that 2x + 3x^2 is the same as 5x^3. Which statement shows that it is NOT the same?
A. 2x+3^2=5x^2
B. 2(6)x3(6)^2not equal to 5(6)^3
C. 2x +3x not equal to 5x
D. 2(4) +3(4)^2 not equal to 5 (4)^3