x + 7y + 3z
Explanation:
The expression: 4x + 2y + 6z - 3x + 5y - 3z
collect like terms by bringing same letters together:
= 4x - 3x + 2y + 5y + 6z - 3z
= x + 7y + 3z
Since the letters are different, we can't simplify any further
The simplified form: x + 7y + 3z
