(2y)⁴
(2y)(2y)(2y)(2y)
16y⁴
Answer:
see explanation
Step-by-step explanation:
there is a difference of - 9 between the 3rd and 4th terms. indicating the sequence could be arithmetic , then
a₂ - a₁ = a₃ - a₂ , that is
k - 17 = - 1 - k ( add k to both sides )
2k - 17 = - 1 ( add 17 to both sides )
2k = 16 ( divide both sides by 2 )
k = 8
The sequence is 17, 8, - 1, - 10
The nth term of an arithmetic sequence is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 17 and d = - 9 , then
= 17 - 9(n - 1) = 17 - 9n + 9 = 26 - 9n
C
one way to solve is to use the method of completing the square
subtract 3 from both sides
x² - 2x = - 3
add ( half the coefficient of the x-term )² to both sides
x² + 2(- 1 )x + 1 = - 3 + 1
(x - 1)² = - 2
take the square root of both sides
x - 1 = ± √(- 2) = ± i√2 ( add 1 to both sides )
x = 1 ± i√2 → C