2500 - 240 = 2260      
2260/2= 1130 or female count        1130 + 240 =  1370 or male count\
1370 + 1130 = 2500
        
             
        
        
        
Its simple, graph them.
For the first equation, go on the Y-Axis (the vertical one) and go to 4. Then from there go up 1, right 6.
For the second equation go on the Y-Axis (the vertical one) and plot a point at 1 (aka 0,1) Now you go up 1, right 3.
When you see an equation like y=2x+3, the 3 represents the point (0,3) as when the x is 0, y=3. Just plug the numbers in. And as for the "2x" 2 is the slope. Slope is always rise/run or up, then right. So if its 2 your slope is 2/1, rise 2, over 1. If it "-2x" is your slope then all you have to do is go down 2, right 1. 
I hope this cleared up your confusion, brainliest/heart would help.
 
        
             
        
        
        
I can’t seen the question so it is hard to answer
        
                    
             
        
        
        
The answer is 5. 
you can turn it into a fraction ratio (6 over 15 is equal to 2 over c) and then cross multiply
        
                    
             
        
        
        
A is correct because the f represents the lilies and then you add the 15 because that is how much roses there are going to be. Lastly just multiply the ten that will give you the answer