ANSWER

EXPLANATION
The given problem is

This is defined if and only if

Even the given expression can be simplified to obtain:

The exclusion is

Try comparing your solution with the following:
Solution:

Answer:

Check:
![2[10-13(\frac{40}{17})]+9(\frac{40}{17})=-34(\frac{40}{17})+60\\-20=-20](https://tex.z-dn.net/?f=2%5B10-13%28%5Cfrac%7B40%7D%7B17%7D%29%5D%2B9%28%5Cfrac%7B40%7D%7B17%7D%29%3D-34%28%5Cfrac%7B40%7D%7B17%7D%29%2B60%5C%5C-20%3D-20)
<em>Hope this was helpful.</em>
Maybe 10 or something i dont know im only 10 so i cant really answer that i just need points
Answer:
two
Step-by-step explanation:
its really easy if u think abt it
We will use demonstration of recurrences<span>1) for n=1, 10= 5*1(1+1)=5*2=10, it is just
2) assume that the equation </span>10 + 30 + 60 + ... + 10n = 5n(n + 1) is true, <span>for all positive integers n>=1
</span>3) let's show that the equation<span> is also true for n+1, n>=1
</span><span>10 + 30 + 60 + ... + 10(n+1) = 5(n+1)(n + 2)
</span>let be N=n+1, N is integer because of n+1, so we have
<span>10 + 30 + 60 + ... + 10N = 5N(N+1), it is true according 2)
</span>so the equation<span> is also true for n+1,
</span>finally, 10 + 30 + 60 + ... + 10n = 5n(n + 1) is always true for all positive integers n.
<span>
</span>