2007-05-21 12:52:12 · 9 answers · asked by julix3x3 1 in Science & Mathematics ➔ Mathematics
If you meant (3/4)xb - ..., then the answer is:
[(15 - 8 - 10)b] / 20 = -3b/20
If you meant 3/(4b) - ..., then the answer is:
(15 - 8 - 10) / (20b) = -3/(20b)
2007-05-21 12:57:11 · answer #1 · answered by fdelley 2 · 0⤊ 1⤋
you have to find a common denominator which is 20, so: 3/4b=15/20b, 2/5b=8/20b, and 1/2b=10/20b
and 15-8-10= -3,
sooooo -3/20 is the answer if im not mistaken
2007-05-21 19:58:26 · answer #2 · answered by tinkerbell 3 · 0⤊ 0⤋
Factor out a b
b(3/4-2/5-1/2)
Then get a common denominator--in this case, the smallest number that 4, 5, and 2 all go into is 20
So you have to figure out what to multiply the top and bottom of the fractions by to get a 20 in the denominator. For 3/4, you have to multiply that fraction by 5/5. For 2/5, multiply by 4/4. For 1/2, multiply by 10/10.
b(15/20-8/20-10/20)
Now you can act on the numerators, subtracting 15-8-10
b(-3/20)
So your answer is -3b/20
2007-05-21 20:03:39 · answer #3 · answered by kasey r 2 · 0⤊ 0⤋
3/4b - 2/5b - 1/2b?
= 15/20b - 8/20b -10/20b = -3/20b
2007-05-21 19:59:02 · answer #4 · answered by ironduke8159 7 · 0⤊ 0⤋
Is the b on the bottom or top?
Common denominator
15/20b-8/20b-10/20b
-3/20b
2007-05-21 19:57:05 · answer #5 · answered by chess2226 3 · 0⤊ 0⤋
15/20b - 8/20b - 10/20b = -3/20b
2007-05-21 19:57:55 · answer #6 · answered by The_Cookie_Goddess 3 · 0⤊ 0⤋
=20* (3/4b - 2/5b - 1/2b)
= 15b - 8b -10b
= -3b
2007-05-21 19:57:35 · answer #7 · answered by sjcpunx408 3 · 0⤊ 2⤋
15/20b-8/20b=7/20b-10/20b= -3/20b
2007-05-21 20:01:11 · answer #8 · answered by heyits.katie 1 · 0⤊ 0⤋
1/8b
2007-05-21 19:59:53 · answer #9 · answered by xyz 6 · 0⤊ 0⤋