Holly would have to climb 92 flights of stairs in the fifth week
Find the next two terms in the given sequence, then write it in recursive form. A.) {7,12,17,22,27,...} B.) { 3,7,15,31,63,...}
iren [92.7K]
Answer:
A) a_n = 5n + 2
B) a_n = (2^(n + 1)) - 1
Step-by-step explanation:
A) The sequence is given as;
{7,12,17,22,27,...}
The differences are:
5,5,5,5.
This is an arithmetic sequence following the formula;
a_n = a_1 + (n - 1)d
d is 5
Thus;
a_n = a_1 + (n - 1)5
Now, a_1 = 7. Thus;
a_n = 7 + 5n - 5
a_n = 5n + 2
B) The sequence is given as;
{ 3,7,15,31,63,...}
Now, let's write out the differences of this sequence:
Differences are:
4, 8, 16, 32
This shows that it is a geometric sequence with a common ratio of 2.
In the given sequence, a_1 = 3 and a_2 = 7 and a_3 = 15
Thus, a_2 = 2a_1 + 1
Also, a_(2 + 1) = 2a_2 + 1
Combining both equations, we can deduce that: a_(n + 1) = 2a_n + 1
Thus; a_n can be expressed as:
a_n = (2^(n + 1)) - 1
Answer:
Option: c is correct.
Step-by-step explanation:
We are given that paco needs at least 3/8 yard of twine to build a model ship.
that is we require twine of amount greater than 3/8 yards.
<em>now we need to check among the given options which quantity is greater than 3/8 yards.</em>
a)
3/10 yard.
As we know that for two rational numbers with the same numerator but with different denominator the number whose denominator is smaller is a greater quantity.
Hence 3/10 < 3/8
Hence option a is incorrect.
b)
1/4 yard
As to compare to rational numbers we have to either make the numerator equal or their denominator equal. Hence here we multiply and divide 1/4 by 2 to get 8 in the denominator.

as 2/8 < 3/8
since the denominator is same and the number with the same denominator but with different numerator are compared as whose numerator is greater is a greater quantity.
Hence option b is incorrect.
c)
3/4 yard
Clearly both the numbers have the same numerator but different denominator and we know that for two rational numbers with the same numerator but with different denominator the number whose denominator is smaller is a greater quantity.
Hence 3/8 < 3/4
Hence, option c is correct.
d)
1/8 yard
clearly both the numbers have the same denominator and we know that for two rational numbers withe same denominator but with different numerator the number whose numerator is smaller is a smaller quantity.
Hence, 1/8 < 3/8
Hence, option d is incorrect.
Answer:
3
Step-by-step explanation:

And,
$ \sum (2i+1)= \sum (2i)+ \sum_{i=1} ^{4} (1) $
$=\sum_{i=1} ^{4}(2i) + 1+1+1+1 $
$=\boxed{\Big(\sum_{n=1} ^{4}(2n)\Big) +4}.... \text{Variable in Summation doesn't matter}$
Hence the difference is 3.