if 1 is subtracted from the numerator of a fraction, the value of the resulting fraction is 1/2. However, if 7 is added ro the denominator of the original fraction, the value of the resulting fraction is 1/3. find the original fraction.
2007-03-26 13:48:09 · 6 answers · asked by aiverson23@sbcglobal.net 1 in Education & Reference ➔ Homework Help
can you exolain how to do it?
2007-03-26 13:56:20 · update #1
5/8.
2007-03-26 13:51:12 · answer #1 · answered by L Dawg 3 · 0⤊ 0⤋
It's basically a guess and check problem. What I did was make a list of equivalent fractions of 1/2 like 2/4, 3/6, 4/8, 5/10.....Then I did the same for 1/3 like 2/6, 3/9, 4/12, 5/15.....Looking at the denominators I see 8 + 7 =15 and 5/15 = 1/3. The answer must be 5/8 because if I subtract 1 from 5 I get 4/8 which is equal to 1/2 !!!!!
2007-03-26 21:04:00 · answer #2 · answered by dpirsq2 5 · 0⤊ 0⤋
A fraction can be described as p/q where p and q are integers. So your word problem becomes:
(p -1)/q = 1/2
p/(q+7) = 1/3
Solve by cross-multiplying. 2(p-1) = q and 3p = q+7
Substitute the first into the second: 3p = 2(p-1)+7
Simplify: 3p = 2p-2+7; 3p = 2p+5; p = 5
Plug back in to find q: q = 2(5-1) = 8
Verify against the original word problem. Works. The original fraction was 5/8.
2007-03-26 21:10:27 · answer #3 · answered by tedfischer17 3 · 0⤊ 0⤋
5/8
2007-03-27 19:18:07 · answer #4 · answered by siddartha t 2 · 0⤊ 0⤋
5/8
2007-03-26 20:55:29 · answer #5 · answered by Isosohungy 1 · 0⤊ 0⤋
1/4
2007-03-26 20:54:55 · answer #6 · answered by D.O.G. Luvr 1 · 0⤊ 0⤋