Answer:
whats the question?
Step-by-step explanation:
Answer:
y = (x - 4)² - 25
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
To obtain this form use the method of completing the square.
Given
y = (x + 1)(x - 9) ← expand factors using FOIL, thus
y = x² - 8x - 9
To complete the square
add/subtract ( half the coefficient of the x- term )² to x² - 8x
y = x² + 2(- 4)x + 16 - 16 - 9
= (x - 4)² - 25 ← in vertex form
The formula for an arithmetic sequence is as follows:
In this formula, 
represents the 
th term of the sequence and 
represents the common difference between each term.
Plug in the known values.
Subtract.
Multiply.
Add.
