First you bring the x to one side so u subtract 4x from 7x and you get the new equation as -9=3x+12 then you just solve and you get x is equal to -7
        
                    
             
        
        
        
1 because 10/9= 1 1/10 
which is closer to 1
        
                    
             
        
        
        
Answer:
32 mi
Step-by-step explanation:
Solve using proportions.

Find the scale factor (how to get from left to right)
To get from left numerator to right numerator, multiply by 4.
(1/2) X 4 = 2
The scale factor is 4.
Multiply the left denominator by the scale factor to get "y".
8 mi X 4 = 32 mi
Therefore 2 inches represent 32 miles.
 
        
             
        
        
        
Not sure question is complete, assumptions however 
Answer and explanation:
Given the above, the function of the population of the ants can be modelled thus:
P(x)= 1600x
Where x is the number of weeks and assuming exponential growth 1600 is constant for each week 
Assuming average number of ants in week 1,2,3 and 4 are given by 1545,1520,1620 and 1630 respectively, then we would round these numbers to the nearest tenth to get 1500, 1500, 1600 and 1600 respectively. In this case the function above wouldn't apply, as growth values vary for each week and would have to be added without using the function.
On one hand, the function above could be used as an estimate given that 1600 is the average growth of the ants per week hence a reasonable estimate of total ants in x weeks can be made using the function.