<span> To get an explicit formula, we need to find an expression which gives the n-th term without having to compute earlier terms in the sequence. Looking at the numbers, and from the recursive formula, we see that the sequence is built by subtracting n from the previous term. This is similar to the triangular number sequence 1,3,6,10,15,... which has the explicit formula a_n = n(n+1)/2. In our case we are subtracting n from the previous term, so we multiply by -1/2 instead of 1/2. However, we also need to add a constant term to reproduce the numbers of the sequence. We can write a_1 = -1(2)/2 + c = 8. Therefore, c = 9.
So the explict formula is:
a_n = -n(n+1)/2 + 9</span>
Answer:
a=-b
Step-by-step explanation:
Or,
b=-a
Width of the rectangle is 16 cm
Step-by-step explanation:
- Step 1: Let the width of the rectangle be x. Then length = 4x. Find width.
Area of the rectangle = length × width
⇒ 1024 = x × 4x
⇒ 4x² = 1024
⇒ x² = 1024/4 = 256
⇒ x = √256 = 16
Answer:
Inequality: 8.25x + 54 = 9.75
Step-by-step explanation:
Why?
It will take 36 hours for David to have as much as Fatima.
David :
Initial saving = 54
Pay per hour = $8.25
While Fatima :
Pay per hour = $9.75
Let number of hours worked = x
David's total = $8.25x + 54
Fatima's total = 9.75x
In other to have the same amount :
8.25x + 54 = 9.75x
The like terms :
8.25x - 9.75x = - 54
-1.5x = - 54
x = - 54 / - 1.5
x = 36
Therefore, it’ll take 36 hours for David to have as much as Fatima.