4/3
40/30
60/45
Simply multiply or divide both the 20 and the 15 to get an equivalent ratio.
        
                    
             
        
        
        
Graphs like these (lines) come in the form y = mx + b where m is the slope and b is the y intercept. Y intercept is where the graph intersects the y axis so the value would be 5
        
                    
             
        
        
        
The nth term is 6n^2-11n+16
        
             
        
        
        
3(-1.5) + 4 = -0.5
3(0.5) + 4 = 5.5