Both of them have consecutive denominators so how can I rewrite?
2007-10-06 18:33:14 · 8 answers · asked by noelle c 2 in Science & Mathematics ➔ Mathematics
3 / 8 = 21 / 56
5 / 7 = 40 / 56
2007-10-10 08:17:22 · answer #1 · answered by Como 7 · 0⤊ 0⤋
the easiest way to find a common denominator is to just times them together in this case it will be 8*7= 56
then you need to times the numerator by the other fractions denominator
(3*7)/56 and (5*8)/56
giving
21/56 and 40/56
2007-10-06 18:45:02 · answer #2 · answered by Anonymous · 0⤊ 1⤋
well, you want the denominators to be the same, right? so, multiply each fraction by the other's denominator. so take 3/8 and multiply the top and bottom by the denominator of 5/7 (which would be 7). then do the same to the other. take 5/7 and multiply the top and bottom by the denominator of 3/8 (which would be 8). then both denominators are equal to 56. and you can add them... if need be, because they are of the same units/numbers...yeah.
2007-10-06 18:42:52 · answer #3 · answered by lollibee 3 · 0⤊ 1⤋
Simply multiply both fractions numerator by the denominator of the opposite fraction, and then multiply the denominator together.
Example:
(3/8) + (5/7) = ?
[(3*7)+(5*8)]/(8*7) = ?
(21 + 40) / 56 = ?
61 / 56
Hope that helps!
2007-10-06 18:41:45 · answer #4 · answered by Dan 2 · 0⤊ 2⤋
3/8=21/56
5/7=40/56
2007-10-06 18:40:43 · answer #5 · answered by Confused guy 2 · 0⤊ 1⤋
21/56 and 40/56 i believe.
Cause 7 and 8 don't have any common multiples or whatever its called.. so you have to multiply them by eachother to get 56. Then you gotta do 3x7 and 5x8....
2007-10-06 18:42:10 · answer #6 · answered by Tamsin 7 · 0⤊ 1⤋
If you don't do you homework yourself you'll never learn.
2007-10-06 18:41:21 · answer #7 · answered by Anonymous · 1⤊ 2⤋
use the LCD.
2007-10-06 18:41:50 · answer #8 · answered by Ted 3 · 0⤊ 1⤋