Answer:
Percentage increase = 269%
Step-by-step explanation:
Price of a DVD last week = $2.87
Price of the same DVD this week = $10.59
Increase in the price of DVD between last week and this week = 10.59 - 2.87
= $7.72
Therefore, percentage increase in the price of DVD = 
= 
= 268.99
= 269%
The sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Given,
18th term of an arithmetic sequence = 8.1
Common difference = d = 0.25.
<h3>What is an arithmetic sequence?</h3>
The sequence in which the difference between the consecutive term is constant.
The nth term is denoted by:
a_n = a + ( n - 1 ) d
The sum of an arithmetic sequence:
S_n = n/2 [ 2a + ( n - 1 ) d ]
Find the 18th term of the sequence.
18th term = 8.1
d = 0.25
8.1 = a + ( 18 - 1 ) 0.25
8.1 = a + 17 x 0.25
8.1 = a + 4.25
a = 8.1 - 4.25
a = 3.85
Find the sum of 20 terms.
S_20 = 20 / 2 [ 2 x 3.85 + ( 20 - 1 ) 0.25 ]
= 10 [ 7.7 + 19 x 0.25 ]
= 10 [ 7.7 + 4.75 ]
= 10 x 12.45
= 124.5
Thus the sum of the first 20 terms of an arithmetic sequence with the 18th term of 8.1 and a common difference of 0.25 is 124.5
Learn more about arithmetic sequence here:
brainly.com/question/25749583
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Answer:
the simplified expression would be 35
Answer:
30 ft²
Step-by-step explanation:
Area of trapezium = 1/2 (a + b)h
a = 6 ft , b = 9 ft , h = 4 ft
Area = 1/2 (6 + 9) 4
= 30 ft²
