Because it is an equation, we know that whatever is on both sides of the equation must be equal. The initial fraction, 9/24, can be further simplified (both numbers made smaller, divided by a common factor). In this case, 9/24 must be divided by something to be equal to 3/y (the y just means we don’t know it’s value yet). If we know that we can divide 9 by 3 to get 3, then we can divide the denominator of the first side of the equation (24) by 3 to get our answer to y.
Basically, in this case we need to find what number to divide 9 by to end up with 3 (that is 3, as 3x3=9) and divide 24 by that number. 24 divided by 3 is 8, as 3x8=24. So, if we know we can reduce 9/24 into 3/8, we can write that as 9/24=3/8. Therefore, y=8.
Hope this helps, good luck!
