Combine like terms to simplify an expression. For example, all terms with the variable x can be combined into one term. All constants can also be combined.
1) -4x - 10x = -14x
2) -r - 10r = -11r
3) -2x + 11 +6x = 4x + 11
4) 11r - 12r = -r
5) -v + 12v = 11v
6) -8x - 11x = -19x
7) 4p + 2p = 6p
8) 5n + 11n = 16n
9) n + 4 - 9 - 5n = -4n - 5
10) 12r + 5 + 3r - 5 = 15r (the 5 and -5 cancel each other out)
11) -5 + 9n + 6 = 9n + 1
For this case we must express the number "423" in a radical way.
We have to, we can rewrite it as:

So, we have to:

By definition of properties of powers and roots we have:
![\sqrt [n] {a ^ m} = a ^ {\frac {m} {n}}](https://tex.z-dn.net/?f=%5Csqrt%20%5Bn%5D%20%7Ba%20%5E%20m%7D%20%3D%20a%20%5E%20%7B%5Cfrac%20%7Bm%7D%20%7Bn%7D%7D)
So:

Answer:

I hope this helps, let me know if it doesn't make sense
Answer:
9.9.9.9 = ( 9*1) . (9/10) + (0/100) + (9/1000) + (0/10000) +(9/100000)