Answer:
vertex = (- 2, - 36)
Step-by-step explanation:
Given a parabola in standard form : y = ax² + bx + c : a ≠ 0
Then the x- coordinate of the vertex is
= - 
f(x) = 5x² + 20x - 16 is in standard form
with a = 5, b = 20 and c = - 16
= -
= - 2
Substitute x = - 2 into f(x) for corresponding y- coordinate
f(- 2) = 5(- 2)² +20(- 2) - 16 = 20 - 40 - 16 = - 36
vertex = (- 2, - 36)
If it is on sale for 15%, then you are paying 85% (100-15) of the original price.
To find 85% of 850, you do 850*.85 to get $722.50
Hope this helps
30s-18 is the answer jus add all the sides together/ add the like terms then solve it
Average rate=(change in y)/(change in x)
if f(x)=-x/3
r=( f(2)-f(-2) )/(2--2)
r=(-2/3-2/3)/(2+2)
r=(-4/3)/4
r=-4/12
r=-1/3
For a line, this is always true, since all lines have a constant velocity, the average velocity over any interval is equal to the slope.