Can Someone Explain this to me?

5x-3y-16=0
4x-5y-5=0

Solution Set:
x| 2 |5 5(2)-3-16 5(5)-3y-16=0
y|-2 |3 10-3y-16 25-36-16=0
3y=16-10 36=16-25
3y=6 3y=9
3 3 y=-2 3 3 y=3

x|5|0 4(5)-5y-5=0 -5y-5=0
y|3|-1 20-5y=0 -5y=5

Question

Can Someone Explain this to me?

5x-3y-16=0
4x-5y-5=0

Solution Set:
x| 2 |5                  5(2)-3-16                5(5)-3y-16=0          
y|-2 |3                 10-3y-16                     25-36-16=0
                            3y=16-10                               36=16-25
                            3y=6                                       3y=9
                            3    3 y=-2                               3    3  y=3 
  
x|5|0                   4(5)-5y-5=0             -5y-5=0
y|3|-1                   20-5y=0                 -5y=5

anonymous · Answer

in the first equation, put 2 in place of x....u'll get the value of y...again...put x=5...u'll get y=3.....
now try it for the second equation....