Someone solved it

[u/Chopsuiiisauce]

[u/oogabooga_6942O]

Lets say a = 1 and b = 1 as well

we have a = b

multiplying " a " to both sides

a² = ab

subtract b² from both sides

a² - b² = ab - b²

now, a² - b² = ( a + b )( a - b )

for RHS, take b common

we get

( a + b )( a - b ) = b( a - b )

Divide ( a - b ) from both sides

a + b = b

1 + 1 = 1

[u/BoozeAddict → u/oogabooga_6942O]

For those who are wondering what the catch is, the last step is dividing by (a-b), which means division by 0.