Given that,
Marcel has $8.25 and is only playing $0.25 games. Floyd has $9.75 and is only playing $0.75 games.
Jorge wants to find the number of games after which Marcel and Floyd will have the same amount of money remaining.
The attached figure shows the equation that Jorge had :
8.25-0.25x=9.75-0.75x
Subtract 9.75 to both sides
8.25-0.25x-9.75=9.75-0.75x-9.75
-1.5-0.25x=-0.75x
Add 0.25x to the both sides,
-1.5-0.25x+0.25x=-0.75x+0.25x
-1.5=-0.5x
⇒ x = 3
Jorge is incorrect at step 2 where he taken -0.25x to the RHS such that -0.75x+0.25x, he get 0.5x instead of (-0.5x). Hence, From Step 1 to Step 2, Jorge did not add 0.25x correctly to both sides.
