At first we need to know how to find the distance between two parallel lines
The parallel lines which have the same slope 
If we have two parallel lines ⇒ y₁ = mx + c₁   and    y₂ = mx + c₂
So, the distance between y₁ and y₂ = d = 

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Part (1):=======
<span>The distance between the lines
</span>
<span>
Y₁ = 3x + 10    and       Y₂ = 3x - 20</span>
∴ m = 3  , c₁ = 10  and  c₂ = -20
∴ d = 

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Part (2):=======
<span>The distance between the lines
</span>
Y₁ = <span>3/2 x + 3/2</span>    and       Y₂ = <span>3/2 x - 5</span>
∴ m = 3/2 = 1.5  , c₁ = 3/2 = 1.5   and  c₂ = -5
∴ d = 
 
 
        
        
        
Answer: the answer is 176 miles apart
Step-by-step explanation: Since they are both driving for 2 hours the speed they are going is doubled and then added together to get 176
 
        
             
        
        
        
1. Set up the equation: 2.50C + 8.50D = 90 (C+D=90)
2. Solve for C and D: Number of cats=19 and the Number of dogs=5