how do I reduce these fractions?

Question

How do I reduce these fractions?
720 over 900
42 over 48
13 over 52
16 over 40
16 over 30
8 over 20
Please and thank you! :)

Answer 1

720/900 > 4/5
42/48 > 7/8
13/52 > 1/4
16/40 > 2/5
16/30 > 8/15
8/20 > 2/5
Look for LCD [lower common denominators]. Otherwise, get a scientific calculator.

Answer 2

Represent both the numerators and denominators as prime factors. Multiply the prime factors that are common to both the numerators and denominators together to get a common divisor for the numerators and denominators.
(720/900)/180=4/5
(42/48)/6=7/8
(13/52)/13=1/4
(16/40)/8=2/5
(16/30)/2=8/15
(8/20)/4=2/5
Remember that the numerator and denominator must be divided by the same number. If you have a problem finding the greatest divisor, choose any number that will go into the denominator and numerator. Keep choosing divisors until the fraction is reduced to lowest terms.

Answer 3

Find the largest common number which occurs in both the numerator and denominator of each fraction, then eliminate it from both by dividing the number by itself. For example, in your first fraction, 720 = 180 X 4 and 900 = 180 X 5. So 720/900 is actually the same thing as (180 X 4)/(180 X 5). Remember, when we multiply fractions, we always multiply the numerators together and the denominators together. For that reason, we can re-write the fraction so that it looks like this: (180/180) X (4/5), but it is actually the same as the expression before it. It's just written differently. Now, notice this. We are dividing a number by itself, and we know that whenever we do this, the result is always one (1). But, we are also multiplying another fraction, in this case 4/5, by the number one, and we have seen that when we do this, we make the fraction appear to be different, but it actually isn't. It just contains numbers, called factors, which multiply the value of both the top and bottom of the fraction by the same amount.

Your task is to simply find those factors in both the numerator and denominator and eliminate them by dividing them out. This is the process we call reducing fractions.

Here's a hint. Start dividing through by prime numbers (numbers which have only themselves and one as factors) first. The numbers 2, 3, 5. 7, 11, 13, 17, 19, 23, 29, 31, 37, etc. are all primes. You can find a list of more prime numbers by doing a search on the Internet. Sometimes you can divide through by the same prime number more than once. This means that that number has been used as a power factor in that number. For example, if we can divide through by the prime number 7 twice, then that means that 7^2 = 49 has been used as a factor in that number. Often, more than one prime number has been used as a factor in fractions. So, if you get discouraged, try another prime.

Good luck!

Answer 4

720/900 x (1/10)/(1/10) = 72/90 x (1/9)/(1/9) = 8/10 x (1/2)/(1/2) = 4/5
42/48 x (1/6)/(1/6) = 7/8
13/52 x (1/13)/(1/13) = 1/4
16/40 x (1/4)/(1/4) = 4/10 = 2/5
16/30 x (1/2)/(1/2) = 8/15
8/20 x (1/4)/(1/4) = 2/5
See what I did? I multiplied each by 1/1 using some kind of multiplier of both the numerator and denominator in such a way, and more than once to get the lowest possible. Try a few more on your own and you are there.

Answer 5

Find the largest common denominator of each number and divide each number by the LCD, and that will give you the smallest possible fraction. For example, 13 over 52 would be 1/4, because 13 is the LCD and 13 goes into 13 once, and 52 four times. I hope this helps.

Answer 6

Find a number that goes exactly (no remainder) into both top and bottom. When you've divided top and bottom by this number, check to see if there is still something else. e.g.
720/900 divide both top and bottom by 10, getting
72/90.
You can still divide both of these by 2, so you do that and get
36/45.

Anything else? Yes, 9 goes into both of them. Finish this one by dividing both parts by 9, then go on and use the same method for the others.

Answer 7

720 over 900 is 4 over 5. 42 over 48 is 7 over 8. 13 over 52 is 1 over 4. 16 over 40 is 2 over 5. 16 over 30 is 8 over 15. 8 over 20 is 2 over 5. Your welcome.

Answer 8

1) Divide both by 180. ( 4 / 5 )
2) Divide both by 6. ( 7 / 8 )
3) Divide both by 13. ( 1 / 4 )
4) Divide both by 8. ( 2 / 5 )
5) Divide both by 2. ( 8 / 15 )
6) Divide both by 4. ( 2 / 5 )

Answer 9

to divide find the largest number you can that will divide into both of the numbers

Answer 10

4/5
7/8
1/4
2/5
8/15
2/5