You can put this solution on YOUR website! You need to find the greatest common factor of the numerator (top) and denominator (bottom). In other words, you need to find the biggest number that divides both 15 and 40. Let's first try to find a number that divides both:
15 = (5)(3)
40 = (5)(8)
So 5 divides both 15 and 40. Is 5 the biggest number that divides 15 and 40? Yes, because no number other than 1 divides both 3 and 8. So 5 is the greatest common factor of 15 and 40. Now let's write this fraction out again:
Whenever both the numerator (top) and denominator (bottom) have a common factor, we can cancel out that number to reduce the fraction. In this case, both the numerator and denominator have 5 as a factor, so we can cancel out 5:
Since the largest number that divides both 3 and 8 is 1, we can't cancel anything else out. So is the simplest form of our original fraction.
(