I can't figure it out! I keep messing up, I think. Here's what I did, where are my mistakes?:
(15)/(8y)=(21)/[4(y-3)]
15[4(y-3)]=21(8y)
Distribute 4 and 21
15(4y-12)=168y
Distribute 15 now
60y-180=168y
subtract 60y from both sides
-180=108y
Divide both sides by 108
y=1(2/3) or 1.666667
But, then I plug y in, and it's wrong. I can't find the problem
2007-10-26 10:24:30 · 6 answers · asked by Samantha 2 in Science & Mathematics ➔ Mathematics
It's still wrong even when I forget to make it negative-that's NOT the problem.
2007-10-26 10:31:55 · update #1
15/8y=21/4(y-3)
15( 4(y-3))=168y
15(4y+12)=168y
60y-180=168y
-180=108y
y=-1.6_
2007-10-26 10:40:49 · answer #1 · answered by msmgloria 2 · 0⤊ 0⤋
(15)/(8y)=(21)/[4(y-3)]
15[4(y-3)]=21(8y) ok
Distribute 4 and 21
15(4y-12)=168y ok
Distribute 15 now
60y-180=168y ok
subtract 60y from both sides
-180=108y ok
Divide both sides by 108 ok
y=1(2/3) or 1.666667 <- problem here.
You forgot the minus sign:. y= -1 2/3
2007-10-26 17:27:25 · answer #2 · answered by ignoramus 7 · 0⤊ 0⤋
(15)/(8y)=(21)/[4(y-3)]
15[4(y-3)]=21(8y)
Distribute 4 and 21
15(4y-12)=168y
Distribute 15 now
60y-180=168y
subtract 60y from both sides
-180=108y
after Divide both sides by 108 it should be
y= -5/3 or -1.666667
2007-10-26 17:39:58 · answer #3 · answered by Wai Choong Shum 2 · 0⤊ 0⤋
You forgot in the last step that 180 is negitive. right answer with the wrong sign.
2007-10-26 17:29:37 · answer #4 · answered by J D 5 · 0⤊ 0⤋
You lost the minus sign when you divided by 108.
2007-10-26 17:28:58 · answer #5 · answered by richarduie 6 · 0⤊ 0⤋
I don´t thinked about, my ingles is poorly
2007-10-26 17:30:55 · answer #6 · answered by Anonymous · 0⤊ 1⤋