What fraction is equivalent to 42 63?

42/63= 2/3.

Look for common factors.

You can express 42 as 6 x 7

You can express 63 as 9 x 7

Divide by the common factor of 7, and you get 6/9

6 can be expressed as 2 x 3

9 can be expressed as 3 x 3

Divide by the common factor of 3 and you get 2/3

There are no more common factors, so thats your answer.

If you're smart, you'd see that 21 was a common factor too, taking you straight to 2/3, but in general, its simpler to find and use smaller factors and repeat the process until there are no more factors.