Answer:
vertex = (2, - 9 )
Step-by-step explanation:
Given a quadratic in standard form : ax² + bx + c : a ≠ 0
Then the x- coordinate of the vertex is
= - 
x² - 4x - 5 ← is in standard form
with a = 1, b = - 4, thus
= - 
= 2
Substitute this value into the quadratic for corresponding value of y
(2)² - 4(2) - 5 = 4 - 8 - 5 = - 9
vertex = (2, - 9 )
A=$20.20/10gal=$2.02 per gal
B=$26.04/12gal=$2.17 per gal
C=$28.14/14gal=$2.01 per gal
D=$30.45/15gal=$2.03 per gal
So C is the cheapest per gallon.
Answer:
x is in the range [-1,4]
Step-by-step explanation:
I haven't worked with absolute value inequalities in awhile, but let's take a wack at this.
We are given the following inequality:
| 2x - 3 | <= 5
This implies two possible cases:
[1] -5 <= 2x -3
Or
[2] 2x - 3 <= 5
So let's solve x for both of these cases:
[1] -5 <= 2x - 3
-2 <= 2x
-1 <= x
[2] 2x - 3 <= 5
2x <= 8
x <= 4
So from these cases, we can say the following is true:
x >= -1 and x <= 4
Thus, we can write this in the form
-1 <= x <= 4
Or in interval notation:
{ x is element of reals | -1 <= x <= 4}
Also written as
x is in the range [-1,4]
Where the closed brackets represent 1 and 4 as possible answers whereas parenthesis would imply they were not.
Cheers.
4(5x+1)(5x-1) = 0
1. Take out the GCF (in this case, 4)
4(25x^2-1) = 0
2. This can be further factored. Factor the values within the parenthesis
4(5x + 1)(5x -1) = 0
