Answer: 
Step-by-step explanation:
We know that the standard quadratic equation is ax^2+bx+c=0
Let's compare all the given equation to it and , find discriminant.
1. a=2, b= -7, c=-9
So it has 2 real number solutions.
2. a=1, b=-4, c=4

So it has only 1 real number solution.
3. a=4, b=-3, c=-1

So it has 2 real number solutions.
4. a=1, b=-2, c=-8
So it has 2 real number solutions.
5. a=3, b=5, c=3

Thus it does not has real solutions.
The proposal for the price for a number of shirts given by the four companies can be analyzed graphically, given that each price list gives a straight line, and the result presented using a piecewise function approach as follows:

<h3>What is a piecewise function?</h3>
A piecewise defined function is one that has other sub functions which are applied over different intervals of the domain.
The given table of values and equation are plotted on a graph using MS Excel
From the graph, and the table created, we have:
When the number of shirts on order is less than 40, the least expensive is Easy Calculation shirts
When the number of shirts are more than 40 but less than 80, the least expensive proposal is given by Shirtee
When the number of shirts to be ordered is more than 80, the company that gives the least expensive proposal is T-Shirts R Us
The selection table is presented as follows:

Learn more about piecewise defined functions here:
brainly.com/question/18499561
#SPJ1
Answer:
D 1.33
Step-by-step explanation:
B and C are less than 1
A is one and .30
D is one and .33
33>30
Speedy Taxis
you will put 30 instead of X in each equation and see which one is the cheapest
you put 30 beacuse it is said 30 miles and also said That X is the mile
Do you understand?
Ans: 1.1 miles more
Speed = distance/time
Time is 1/5 of an hour
1/5 of 1hr = 1/5 or 0.2 hrs
Speed = 16 mph
So, we're after distance.
Distance = speed x time
= 16mph x 0.2
= 3.2 miles
Walks for 3/7 hour at 5 miles per hour :
Time & speed given, distance is what we're after.
(3/7 of 1hr is 3/7)
Distance = speed x time
= 5mph x 3/7
= 15/7 miles or 2.14285...miles
So, distance is about 2.1 miles to 1 d.p
Thus, 3.2 - 2.142... (the full ans) = 1.057... miles
Well, he biked 1.06 miles or 1.1 miles (depending on how you want to round it) more than walking.
Hope this helps!