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:
The length is 7 m
The width is 10 m
Step-by-step explanation:
length = x
width = 2x - 4
length * width = area
It is given that the area is 70 
From there
x * (2x - 4) = 70
- 4x = 70
- 4x - 70 = 0
- 2x - 35 = 0
Now we have a quadratic equation, which is a + bx + c = 0, where a 
0
In this equation a = 1, b = -2 and c = -35
Discriminant (D) formula is b² - 4ac
D = 
- 4 * 1 * (-35) = 144 > 0
This discriminant is more than 0, so there are two possible x
Their formulas are 
and 
= 
= -5 < 0 (the length of the rectangle has to be more than 0, so we don't use this x)
= 
= 7 > 0 (this one is right)
Calculating the dimensions
length = x = 7 (m)
width = 2x - 4 = 2 * 7 - 4 = 10 (m)
Answer:
B) 625
Step-by-step explanation:
(-5)^4
-5*-5*-5*-5
25*25
625
You would fill in 9 for x so your equation would be 2(9)+3 and you would then get 21. Therefore the answer is f(x)=21
