Question 118486
25x + 10(2x-4) + 5(2x) = 510                          
25x + 20x - 40 + 10x = 510                    
45x - 40 + 10x = 510                          
55x - 40 = 510                                  
55x = 550                                         
x = 10                                                  

Check
25(10)+10(2(10)-4)=510
250+10(20-4)+5(20)=510
250+10(16)+100=510
250+160+100=510
510=510

There are 10 quarters, 16 dimes, and 20 nickels.