The explicit formula for arithmetic sequence is:
an=a+(n-1)d
where:
a=first term
d=common difference
given:
a3=22
a(17)=-20
substituting this in our equation we get:
22=a+(3-1)d
22=a+2d
a=22-2d........i
also:
-20=a+(17-1)d
-20=a+16d.....ii
but substituting i in ii we get:
-20=22-2d+16d
-20-22=14d
-42=14d
d=-3
but:
a=22-2d
a=22-2(-3)
a=28
thus the formula will be:
an=28-3(n-1)
thus the first term will be 28
the 2nd term will be:
a2=28-3(2-1)
a2=25
the 3rd term will be:
a3=28-3(3-1)
a3=28-6
a3=22
a4=28-3(4-1)
a4=28-9
a4=15
a5=28-3(5-1)
a5=28-3(4)
a5=28-12
a5=15
Answer:
There's not enough information to answer the question.
Step-by-step explanation:
The question says that out of 84 kids, 3/7 bought their lunches. Then it asks how many of the 3/7 got pizza without providing a number of those who bought a different food. And so, there's not enough information to solve this question.
If at least one has to be heads then it would be 1/5
Answer:
Step-by-step explanation:
AB = 8x + 5
BC = 5x² - 16
5x² - 16 = 8x + 5
5x² - 8x - 21 = 0
Quadratic formula
x = [8 ± √(8² – 4·5(-21))] / [2·5]
= [8 ± √484] / 10
= [8 ± 22] /10
= -1.4, 3
-1.4 is an extraneous solution.
x = 3
AB = 8x+5 = 29
AC = 58
Answer:
C
Step-by-step explanation:
Now we have improved on that. We have got the biggest marble-cutting establishment on earth within a hundred yards of that grave. We have got a half-dozen woolen mills right around it, and iron mines, and iron furnaces, and iron factories. We are coming to meet you. We are going to take a noble revenge, as my friend, Mr. Carnegie, said last night, by invading every inch of your territory with iron, as you invaded ours twenty-nine years ago.