2/15 + 8/21 =
9/16 - 1/12 =
2007-01-14 16:42:14 · 5 answers · asked by imalostcause..searching569 2 in Science & Mathematics ➔ Mathematics
Please help! It's been a long time since I did fractions, I'm 30. Anyway, can some one help me with these?:
2/15 + 8/2
9/16 - 1/12
Thank You so much for your help!!
2007-01-14 16:49:42 · update #1
1.LCM=105
14+40/105
=54/105
=18/35
2.LCM=48
=27-4/48
=23/48
2007-01-14 16:56:19 · answer #1 · answered by raj 7 · 1⤊ 0⤋
2/15 + 8/21 =
Find the LCD:
15 = 3*5, 21 = 3*7, LCD = 3*5*7 = 105
(2*105)(15*105 = (8*105)/21*105) =
( 2*7 + 8*5)/105 =
(14 + 40)/105 =
54/105 =
18*3/35*3 =
18/35
9/16 - 1/12 =
16 * 2*2*2*2, 12 = 2*2*3, LCD = 2*2*2*3 = 48
(3*9 - 1*4)/48 =
(12 - 4)/48 =
8/48 =
8/(6*8) =
1/6
2007-01-15 01:09:13 · answer #2 · answered by Helmut 7 · 0⤊ 0⤋
well...
2/15+8/21=14 / 105 + 40 / 105=54/105.
the first problem's answer is 54/105.
and now...
9/16+1/12=27 / 48 - 4 / 48=23/48.
the second problem's answer is 23/48.
2007-01-15 01:39:46 · answer #3 · answered by blah 3 · 0⤊ 0⤋
find a common denominator!
the common denominator for 15 and 21 is 3*5*7=105
The new fractions are 14/105 + 40/105 = 54/105 reduce to 18/35.
The common denominator for the second is 4*4*3=48
27/48 - 4/48= 23/48
2007-01-15 00:57:02 · answer #4 · answered by christopher_az 2 · 2⤊ 0⤋
need to get LCD
2/15 + 8/21 =
14/105+40/105=44/105
9/16 - 1/12 =27/48-4/48=23/48
2007-01-15 01:27:48 · answer #5 · answered by yupchagee 7 · 0⤊ 0⤋