These would be 2 of the 4 equations, because 6 times 9 equals 54 and 9 times 6 equals 54, but are written in a different way. Thus meaning they are 2 of the 4 equations.
These 2 would be the final to, because 54 divided by 6 is 9, and 54 divided by 9 is 6. Thus meaning they are the final 2 equations.
I hope this helps!
