Answer:
Step-by-step explanation:
Geometric sequence
Each term in a geometric sequence can be computed as the previous term by a constant number called the common ratio. The formula to get the term n is
where 
is the first term of the sequence
The problem describes Georgie took 275 mg of the medicine for her cold in the first hour and that in each subsequent hour, the amount of medicine in her body is 91% (0.91) of the amount from the previous hour. It can be written as
amount in hour n = amount in hour n-1 * 0.91
a)
This information provides the necessary data to write the general term as
b)
In the 8th hour (n=8), the remaining medicine present is Georgie's body is
20/3 - Take the 6 2/3, multiply the 6 and the 3 (6 x 3 = 18), then add the 2 (18 + 2 = 20). Put that number over the original 3 and you've got yourself a mixed number.
Answer:
I’m pretty sure it’s Jeremiah
Step-by-step explanation:
Let n = length
let n-4 = width since it is 4 meters shorter
2( n+n-4) =72 Two of the length and width added together equal the perimeter
combine like terms
2(2n -4) = 72 Now use the distributive law on the left side of the equation
4n -8 = 72 Now add 8 to both sides
4n -8 +8 = 72 +8
4n = 80 Finally divide each side by 4
n=20
so the length is 20 and the width is 4 less or 16.
Let's see if our answer works.
20 + 16 + 20 +16 =? 72
72 =72 yes, it does. Length = 20 Width = 16
Answer:
Options (3), (4) and (5)
Step-by-step explanation:
1). a² - 9a + 7ab + 63b
= a(a - 9) + 7b(a + 9)
Now we can not solve this problem further.
Therefore, can't be factored by grouping.
2). 3a + 4ab - b - 12
= a(3 + 4b) - 1(b - 12)
We can't solve it further.
Therefore, can't be factored by grouping.
3). ab + 6b - 2a - 12
= b(a + 6) - 2(a + 6)
= (b - 2)(a + 6)
We can be factored this expression by grouping.
4). x³ + 9x²+ 7x + 63
= x²(x + 9) + 7(x + 9)
= (x² + 7)(x + 9)
Therefore, the given expression can be factored by grouping.
5). ay² + a - y² - 1
= a(y² + 1) - 1(y² + 1)
= (a - 1)(y² + 1)
This expression can be factored by the grouping method.
Options (3), (4) and (5) are the correct answers.
