This problem is an example of an arithmetic series.
The common difference of the second term (15) with the first term (9) and the third term (21) with the second term (15) [15-9=6; 21-15=6] is 6.
The formula for solving this is:
An= A1 +(n-1)*d where An is the nth term, A1 is the first term, n is the number of terms and d is the common difference.
An=9+ (31-1)*6 = 189
The answer is 189.
Answer:
0.4069 ; 1.843
Step-by-step explanation:
Given:
Base of parallelogram, b = (2x - 1)
Height = (4x - 7)
Area = 1
Area of parallelogram = Base * height
Area of parallelogram = (2x - 1) * (4x - 7)
(2x - 1) * (4x - 7) = 1
8x² - 14x - 4x + 7 = 1
8x² - 18x + 7 - 1 = 0
8x² - 18x + 6 = 0
Divide through by 2
4x² - 9x + 3 = 0
Solving the quadratic equation :
Using the formula
-b ± √(b² - 4ac) / 2a
a = 4 ; b = - 9 ; c = 3
Plugging in the values :
-(-9) ± √((-9)² - 4(4)(3)) / 2(4)
9 ± √(81 - 48) / 8
9 ± √33 / 8
(9 ± 5.7445626) / 8
(9 - 5.7445626) / 8) = 0.4069
(9 + 5.7445626) / 8 = 1.843
