Answer:
5
Step-by-step explanation:
You can express this as a system of equations:
x in this instance will be her present age.
x + 8 = 2x + 3
simply solve for x after this by subtracting three and x from both sides, and you’ll find that x is 5.
Answer:
-2 and -6 is the correct answer
Even numbers end with 2,4,6,8, or 0. Thus, 28 is the even number.
Answer:
- Minimum 100 bicycles
- Minimum cost is 13500
Step-by-step explanation:
<u>Given function:</u>
- C(x) = 3x^2- 600x + 43500
a.
Minimum cost is obtained at vertex.
Vertex is determined by formula x = -b/2a, in standard form of
f(x) = ax^2 + bx + c
<u>Vertex of the given function is:</u>
b.
<u>Cost at vertex is:</u>
- C(100) = 3*100^2 - 600*100 + 43500 = 13500
The sum of any arithmetic sequence is the average of the first and last terms times the number of terms.
Any term in an arithmetic sequence is:
a(n)=a+d(n-1), where a=initial term, d=common difference, n=term number
So the first term is a, and the last term is a+d(n-1) so the sum can be expressed as:
s(n)(a+a+d(n-1))(n/2)
s(n)=(2a+dn-d)(n/2)
s(n)=(2an+dn^2-dn)/2
However we need to know how many terms are in the sequence.
a(n)=a+d(n-1), and we know a=3 and d=2 and a(n)=21 so
21=3+2(n-1)
18=2(n-1)
9=n-1
10=n so there are 10 terms in the sequence.
s(n)=(2an+dn^2-dn)/2, becomes, a=3, d=2, n=10
s(10)=(2*3*10+2*10^2-2*10)/2
s(10)=(60+200-20)/2
s(10)=240/2
s(10)=120
