Question

(4x3 + x2 + 2x)
+ (3x3 + x2 + 4x)

Answer 1

(4•3+x2+2x)+(3•3+x2+4x)

You combine alike terms inside the parentheses giving you:

(12+4x)+(9+6x)

Then you take the parentheses away and again combine alike terms giving you your answer.

So it would be 21+10x