Simplifying radical expressions expression is important before addition or subtraction because it you need to which like terms can be added or subtracted. If we hadn't simplified the radical expressions, we would not have come to this solution. In a way, this is similar to what would be done for polynomial expression.
Answer:
Explicit rule, because you can find the 40th term directly using the explicit rule. You would need to find the first 39 terms before finding the 40th terms using recursive rule.
hope this helps...
X=4 because you combine 2+4 and subtract -6 then divide