Question 58419
The question in the book asks: Use substitution to solve the linear system. 
0.25x - 1.25y = 10.25
x - 5y = 20 
My x and y's both cancel out or equal zero. I don't understand. 
Thanks
0.25x - 1.25y = 10.25
            x = 10.25/0.25 + 1.25y/0.25
            x = 41 + 5y
       we can define this equation : x - 5y = 41 (not)x - 5y = 20
           so, 0.25(41+5y)-1.25y = 10.25
                10.25 + 1.25y - 1.25y = 10.25
                  
            Both X and Y are null set, because they were cancelled out.