Answer:
6x -3x^4
Explanation:
Eliminate parentheses. Since the multiplying coefficient is +1, the parentheses can simply be dropped:
= 3x +2x^4 +3x -5x^4
Add like terms (ones with the same exponent on the variable).
= 3x +3x +2x^4 -5x^4 . . . . . . . group like terms together
= (3+3)x +(2-5)x^4
= 6x -3x^4