Answer:
Answer: Sum of first 90 terms is Option d. 11655
Step-by-step explanation:
We have to find the sum of first 90 terms of the sequence -4,-1,2,5,8......
First we find the 90th term of the sequence
As we know the formula A(n)= A(1)+(n-1)d
Given from the sequence
A(1) = (-4)
n=90
d = 3
So A(n) = -4+(90-1)3
= (-4)+89×3
= 263
Now we know formula for the sum of any sequence is
Sum S(n) = 
Now we know n= 90
A(1) = -4
A(n) =263
Now we put the value in the formula
S(n)= 
= 45×259
= 11655
The answer is (7,-1).
x1-y1 and x2-y2 gives you 2-(-5) and 3-4, so you now have a point which is (7,-1) which is the slope.
We are given the electricity cost as 5 cents per
kilowatt-hour. We should notice that the cost is actually in the form of:
electrical cost = cost / (power * time)
Therefore to get a number which is in terms of cents
alone (cost alone), therefore we should multiply the given electrical cost
value with the power and time.
Power = 80 watt = 0.08 kilowatt
Time = 24 hours
Therefore the cost is calculated as:
cost = electrical cost * power * time
cost = [5 cents / (kilowatt hour)] (0.08 kilowatt) (24
hour)
cost = 9.6 cents
Answer:
<span>9.6 cents</span>
