Answer:
= 3n + 77
Step-by-step explanation:
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 = 80 and d = a₂ - a₁ = 83 - 80 = 3 , then
= 80 + 3(n - 1) = 80 + 3n - 3 = 3n + 77
Answer:
x^2 + 18x + 81 complete's the square.
Step-by-step explanation:
y = [x^2 + 18x + (18/2)^2 ] - (18/2)^2
y = [x^2 + 18x + 81] - 81
y = (x + 9)^2 - 81 This is just to make the completion of the square accurate.
You can't just add something to an expression. You have to balance it out.