Answer:
108/5
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
4.4mm
Step-by-step explanation:
Circumference of circle
2 Pi r 
Diameter of coin = 22mm
Therefore the radius = 11mm
Therfroe the outer edge (circumference) 
= 2 Pi r
= 2 x Pi x 11
=69.11mm
For the inner edge
Diameter = 5
Radius = 2.5
Therefroe inner edge (circumference) 
= 2 Pi r
= 2 x Pi x 2.5
= 15.7mm
The difference is 
69.11 - 15.7
=4.4mm
 
        
             
        
        
        
Answer:
Quadratic Formula
so 
x = -5
and
x = 0.5
Step-by-step explanation:
Whenever you see a problem in this form, which you will see a lot of, you can try to factor it or use the "least squares" method or what have you, but those won't always work, unfortunately. 
Fortunately, the quadratic formula will never fail you with quadratic expressions.
This is the Quadratic Formula

a is the the number on the variable with the exponent ^2
b is the number on the variable with no exponent
c is the third number
a and b cannot be equal to 0; c can be 
Since we're looking for a number with an equation that has a square root in it, we're going to get two answers. These two answers come from the radical being separately added AND subtracted from the radical. It's basically two problems.
Plugging  in our numbers to this equation gives us x values of -5 and 0.5. This will always work with polynomials with factors of ^2 in them. 
If you have a TI-84 calculator or newer, there's a tool on it that will factor polynomials like this one for you just by giving it the numbers.
 
        
             
        
        
        
<span>2. scalene, isosceles, equilateral</span>
        
                    
             
        
        
        
Answer:
5r + 3s ≥ 30
Step-by-step explanation:
We know Keiko wants to do exercise at least 30 minutes a day, and she wants ideally to mix up the activities, by combining running and swimming into her schedule.
Since each lap she runs takes 5 minutes and each lap she swims takes 3 minutes, these will be the left side of the inequality:
5r + 3s
She wants to exercise at least 30 minutes a day, so...
5r + 3s ≥ 30
she could do 3 laps of running and 5 laps of swimming for example.