H (x) = 5x^2+40x+64
y = (5x^2+40x+60) + 4
y = 5(x^2+8x+12) + 4
y = 5(x+2)(x+6) + 4
y-4 = 5(x+2)(x+6)
This means that the solutions, or where the parabola crosses the x-axis, are at x+2=0 and x+6=0, or x=-2, -6
So the midpoint of -2 and -6 is -4, the axis of symmetry is x=-4
Four times a number plus twenty one
Answer: f(n+1) = 3 f(n)
Step-by-step explanation:
- A recursive formula is used to determine each term of a sequence using preceding term or terms.
Given sequence : 2.5, 7.5, 22.5, 67.5, 202.5,...
Here,

Common ratio = 3
Let f(n) be a term in this sequence then the next term will be f(n+1) = 3 f(n), where n is a natural number .
Required recursive formula : f(n+1) = 3 f(n)
Answer:
6x+21
Step-by-step explanation: