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:
Step-by-step explanation:
To answer this question, first we need to figure out how much of the board Rafi cut off.
To do this, we need to multiply the length of each piece by the number of pieces he cut off.
3 7/8 = 3.875
3.875 * 3 = 11.625
Now, because we knew Rafi cut off 11.625 feet off of the board, we just need to subtract this length from the length of the entire board to find the remaining length.
15 1/2 = 15.5
15.5 - 11.625 = 3.875
There is 3.875 feet or 3 7/8 of the board left.
Answer:
2√2.
Step-by-step explanation:
We use the Pythagoras Theorem:
x^2 = 2^2 + 2^2
x^2 = 8
x = √8
= 2√2.
Multiple 6 with numbers inside paranthesis:
12x - 66 + 15 = 21
add 66 fhen substrack 15 from both sides :
12x = 72 divide both sides with 12:
x = 6
