Well since you dont have the graphs posted i can tell u the y-intercept and the slope and you can figure it out from there.
8x-y=-4
-y=-8x-4
y=8x+4
the y intercept is 4 and the slope is positive 8
        
                    
             
        
        
        
What is the full question. I would be able to help if I saw it all. 
        
             
        
        
        
c = cost of food/med for cats
d = cost of food/med for dog
y = total cost/spent
What you know:
y = 6c + d              [has 6 cats and 1 dog]   
c = 2/3d - 5        [cost for cat is 5 less than 2/3 cost for dog]
y = $195
y = 6c + d    
Substitute/plug in what you know, plug in (2/3d - 5) for c and 195 for y
195 = 6(2/3d - 5) + d        Distribute/multiply 6 into (2/3d - 5) 
195 = 4d - 30 + d        Combine like terms
195 = 5d - 30      Add 30 on both sides of the equation
225 = 5d        Divide 5 on both sides
$45 = d              
 
        
             
        
        
        
Answer:
one solution
Step-by-step explanation:
3x − 7 = 4 + 6 + 4x
Combine like terms
3x-7=4x+10
Subtract 3x from each side
-7=x+10
Subtract 10 from each side
-17 =x
There is one solution
 
        
             
        
        
        
<span>arc length   =   circumference • [central angle (degrees) ÷ 360]
Solving this equation for circumference:
</span>
<span>circumference = arc length / (central angle / 360)
</span><span>circumference = 12 / (85/360)
</span>circumference = 12 / <span><span>0.2361111111
</span>
</span>
<span>circumference =
</span>
<span>
<span>
<span>
50.8235294118
</span>
</span>
</span>
Source:
http://www.1728.org/radians.htm