10x/4 has to equal something though. In this case it is equal to 1 because you've brought the 4 from the RHS onto the LHS by division: . From here you'd need to divide both sides by 10/4: and since we divide fractions by "flip n multiply" the RHS is the same as
From the line you can divide both sides by 10 because we want to get x on it's own (which is the same as 1x): and since 10/10 is indeed 1 this is the same as which is correct but it's more proper to simplify fractions and so 2/2 was cancelled.
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