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.
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Answer:
it is a 90 degree angle
Step-by-step explanation:
because the little square in the corner
Answer:
a
Step-by-step explanation:
Answer:
Simple interest=$324 Total=2124
Step-by-step explanation:
Simple interest=6%
6% of 1800=108
108x3=324
1800+324=2124
Answer:
Then, it costs $2120 to order 1000 pens and 2000 notebooks.
Step-by-step explanation:
The Students' Union needs to order 1000 pens and 2000 notebooks. The price per pen when buying 1000 of them is 60c. The price per notebook when buying 2000 of them is 76c.
Then the total of money needed to order 1000 pens and 2000 notebooks is:
Total Money = 1000 × 0.60 + 2000 × 0.76 = $2120
Then, it costs $2120 to order 1000 pens and 2000 notebooks.
