Answer:
The model represents the decimal 73. 
Step-by-step explanation:
The model is 10x10. You must count the blue blocks. The number of blue blocks is 73, therefore it represents the decimal 73. (Hope this helped!)
 
        
             
        
        
        
In a slope intercept equation in the form of y=mb+b,
m is the slope. m is the coefficient of x, meaning it is the number x is multiplied by. In this case, m happens to be
-5
which is your answer
        
             
        
        
        
Answer:
variables look like letters of the alphabet.
I hope this helps
 
        
                    
             
        
        
        
Number of dimes: x
Number of quarters:  x + 3
Answer:
B ) 0.10 x + 0.25 ( x + 3 ) = $1.80
Also we can solve this equation:
0.10 x + 0.25 x + 0.75 = 1.80
0.35 x = 1.80 - 0.75
0.35 x = 1.05
x = 1.05 : 0.35
x = 3,  x  + 3 = 6
He has 6 quarters and 3 dimes. 
( 6 * 0.25 + 3 * 0.10 = 1.50 + 0.30 = $1.80 - correct)
        
             
        
        
        
21,500 this is the answer