Add (3x3 - 6
– )
and
(x3 +3)

3x^6+3x^3-18

Step-by-step explanation:

Use the Foil method: (a+b)(c+d)=ac+ad+bc+bd

1. 3x^6+9x^3-6x^3-18

2. Collect like terms 3x^6+(9x^3-6x^3)-18

3. Simplify and that should give you 3x^6+3x^3-18 Hope that helps !

expression #3 is not equivalent. the others are.