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>
Answer:
40
Step-by-step explanation:
because vertical angles are equal
3×40=120
5a - 10*3 = 45
5a - 30 = 45
5a = 45 + 30
5a = 75
a = 15
Answer:
What segments are we SUBTRACTING from ??
<span>Prime factorization of 140/700 = </span>Answer: 140/700 =1/5 = 0.2
