ok i dont know why this is so difficult for me.. the question is 1/3q-6=1/5q
1/3q-6=1/5q.
15/1x1/3q-6=1/5qx15/1
5q-6=3q
5q-3q=6
2q=6
q=3
they say the answer is 60?????? what am i doing wrong???
2007-06-15 03:04:46 · 10 answers · asked by Cat 1 in Science & Mathematics ➔ Mathematics
I assume you mean:
q/3 - 6 = q/5
In that case:
Multiply both sides by 3 --> q - 18 = (3/5)q
Subtract (3/5q from both sides --> q - (3/5)q -18 = 0
Add 18 to both sides --> (2/5)q = 18
Multiply both sides by 5 --> 2q = 90
Divide both sides by 2 --> q = 45 ( not 60)
Check: assume q = 60 as claimed. Then
(1/3)*60 - 6 = (1/5)* 60
20 - 6 = 12
14 = 12 ---> NOT TRUE so 60 can't be right
Let q = 45
(1/3)*45 - 6 = (1/5)*45
15 -6 = 9
9 = 9
This is a true statement, therefore q = 45 is correct
2007-06-15 03:17:07 · answer #1 · answered by nyphdinmd 7 · 0⤊ 0⤋
1/3q-6=1/5q
subtract 1/3q from both sides with a common denominator
-6=-2/15q
multiply both sides by -15/2
90/2=q
45=q
check by placing the answer back into the problem
1/3(45) - 6 = 1/5(45)
15-6=9
9=9
The answer is not 60 as you can see
1/3(60) - 6 = 1/5 (60)
20-6=12
14 = 12 NOPE
The answer key is wrong in this case. . .good luck :)
2007-06-15 10:13:11 · answer #2 · answered by greenbull21 2 · 0⤊ 0⤋
Could you write this with the proper brackets please. There are many possibilities:
(1/3)q - 6, 1/(3q) - 6, 1/(3q - 6), (1/3)(q - 6) for the LHS, and
(1/5)q, 1/(5q) for the RHS.
That gives at least 8 possible equations.
2007-06-15 10:14:29 · answer #3 · answered by Anonymous · 0⤊ 0⤋
First, multiply everything in the equation by 15 because it is the LCM of the denoms.
5q - 90 = 3q
.
.
2q = 90
I get the answer to be
q = 45
2007-06-15 10:11:07 · answer #4 · answered by Math Stud 3 · 0⤊ 0⤋
Assuming you mean
(1/3)q - 6 = (1/5)q
Multiply *everything* by 15
So
5q - 90 = 3q
So 2q = 90
So q = 45
2007-06-15 10:11:24 · answer #5 · answered by tsr21 6 · 0⤊ 0⤋
You forgot to multiply the 6 by 15. Your third line should be
5q – 90 = 3q
Then you get
2q = 90
q = 45.
Hmmm... Unless I've misread your question, this is definitely right, so looks like the answer you have been given is wrong.
2007-06-15 10:12:43 · answer #6 · answered by rrabbit 4 · 0⤊ 0⤋
do you mean 1/3 * q or 1/3q
and 1/5 * q or 1/5q
2007-06-15 10:11:55 · answer #7 · answered by Anonymous · 0⤊ 0⤋
(1/3)q - (1/5)q - 6 + 6 = (1/5)q - (1/5)q + 6
(2/15)q = 6
q = 45
2007-06-15 10:09:31 · answer #8 · answered by yeeeehaw 5 · 0⤊ 0⤋
When you multiplied by 15, you forgot to multiply the 8 by 15 as well.
2007-06-15 10:12:01 · answer #9 · answered by Freddie 2 · 0⤊ 0⤋
put 8 on other side
2007-06-15 10:08:17 · answer #10 · answered by Anonymous · 0⤊ 1⤋