For the first 60 positive integers, a = 1, n = 60, l = 60.
Sn = n/2(a + l)
s = 60/2(1 + 60) = 30(61)
For the next 60 positive integer, a = 61, n = 60, l = 120
Sum = 60/2(61 + 120) = 30(61 + 120) = 30(61) + 30(120) = s + 3600
Sum of first 120 positive integers = s + s + 3600 = 2s + 3600
Answer:
Step-by-step explanation:
Andi needs yards of fabric for a project.
Andi needs more of Fabric.
The value of t should be equals to 6.1 years.
I hope this helps.
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The answer is D an = -5n + 12
Use the formula an = a1 + d(n - 1) to solve
an = 7 + (-5)(n - 1)
an = 7 + (-5n +5)
an = -5n + 12
Initial salary = $50,000 .
Rate of raise = 5% each year.
Therefore, each next year salary would be 105% that is 1.05 times.
5% of 50,000 = 0.05 × 50000 = 2500.
Therefore raise is $2500 each year.
According to geometric sequence first term 50000 and common ratio 1.05.
Applying geometric sequence formula
1)
2) In order to find salary in 5 years we need to plug n=5, we get
= 50000(1.21550625)
<h3>=$60775.3125.</h3>
3) In order to find the total salary in 10 years we need to apply sum of 10 terms formula of a geometric sequence.
Plugging n=10, a = 50000 and r= 1.05.
= 628894.62678.
<h3>Therefore , you will have earned $ 628894.62678 in total salary by the end of your 10th year.</h3>