Answer:
See below 
Step-by-step explanation:
Regularly, 1.25
Now,0.5
So, 

So, the percentage of decrease price is 60%.
 
        
             
        
        
        
Answer:
The y-intercept of the line is 2
Step-by-step explanation:
You could try to find the slope of the line and then find the intercept with y axis by sloving b = y - ax
But here it seems easy enough once you see that the x values in the table increase by a factor of 8 and the y values in the table increase by a factor of 20.
(By the way, this is enough to give you the slope, because it is 8/20 ). But why bother?
Just extrapolate the table to the left, and you will find the y value where x = 0
x 0 8 16 24 32
y 2 22 44 64 84
So the y-intercept of the line is 2.
Extra:
The full equation of the line is:
y = 8/20x + 2
 
        
                    
             
        
        
        
The reciprocal of 7 is 1/7, reciprocal of 8 is 1/8, and reciprocal of 9 is 1/9
        
                    
             
        
        
        
Answer:
The correct answer is b. 
Step-by-step explanation:
The wave equation is given generally as:
c(x, t) = Acos(kx - wt)
Where A = amplitude
k = wave number
w = angular frequency.
x = horizontal distance moves by the wave.
t = time
The options show to us that the wave depends only on t and not (x, t). 
Hence, the wave equation becomes:
c(t) = Acos(wt)
Given that:
A = 5 V
f = 1 * 10⁶ Hz
Angular Frequency, w, is given as:
w = 2πf
w = 2 * π * 1 * 10⁶ Hz
w = 2π(1 * 10⁶)
The wave equation becomes:
c(t) = 5cos(2*π*1*10⁶)
The correct answer is b.