2007-10-12 10:29:43 · 12 answers · asked by samjam555 1 in Science & Mathematics ➔ Mathematics
Its very simple yaar.
First of all see ur equation:
4x/(3x+7)=3/4.
In every sum like this u should cross multiply and get the answer:
4(4x)=3(3x+7)
Now *&÷ for getting the answer:
16x=9x + 21
7x=21
x=3.
In every sum to find x(a,b....z) u should follow the same method but u should knoe the factors.
Try this:
7x/3=(9x-7)/5.
2007-10-12 14:43:09 · answer #1 · answered by Aariz 2 · 0⤊ 0⤋
I think the question is not written correctly.
since,
4x/3x+7=4/3+7=25/3 which is not equal to 3/4.
positioning of bracket is important!
If you mean the question is 4x/(3x+7)=3/4 then it had already been answered by others.
2007-10-15 04:56:30 · answer #2 · answered by Roy 2 · 0⤊ 0⤋
Multiply by 3x+7 to get
4x=3(3x+7)/4
Multiply both sides by 4
16x=3(3x+7)
Distribute
16x=9x+21
Subtract 9x
7x=21
Divide by 7
x=3
2007-10-12 10:36:58 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Multiply by 3x+7 to get
4x=3(3x+7)/4
Multiply both sides by 4
16x=3(3x+7)
Distribute
16x=9x+21
Subtract 9x
7x=21
Divide by 7
x=3
2007-10-12 10:33:40 · answer #4 · answered by Smrt 1 · 0⤊ 0⤋
4x/(3x+7)=3/4
Cross multiply getting:
3(3x+7) = 4*4x
9x+21 =16x
21 = 7x
x = 3
2007-10-12 10:34:13 · answer #5 · answered by ironduke8159 7 · 0⤊ 0⤋
4x/3x+7=3/4
=4x(4)=3(3x+7) [when u cross multiply]
16x=9x+21
16x-9x=21
7x=21
x=21/7=3
x=3
2007-10-12 22:45:58 · answer #6 · answered by Anonymous · 0⤊ 0⤋
is that 4x / (3x+7) = 3/4 <-- Call this A
or 4x/3x+7 = 3/4 <-- Call this B
A,
4x / (3x+7) = 3/4
4x = (3/4) *(3x+7)
16x = 3(3x+7) = 9x +21
21 = 7x
x = 3
B
4x/3x+7 = 3/4
x = (3/4 - 7) * 3/4)
x = -6.25 * 0.75 = -4.6875 or 4 11/16 (four and 11 sixteenths
2007-10-12 10:32:40 · answer #7 · answered by David F 5 · 0⤊ 1⤋
The way you wrote it the x's cancel out and just leaves numbers. Next time use parenthesis around the 3x+7 term.
2007-10-12 11:09:08 · answer #8 · answered by andyg77 7 · 0⤊ 0⤋
4x/(3x+7)=3/4
or 4x*4=3*(3x+7)
or 16x=9x+21
or 16x-9x=21
or 7x=21
or x=3 ans
2007-10-13 09:35:34 · answer #9 · answered by MAHAANIM07 4 · 0⤊ 0⤋
its too easy . transpose4 to 4x and 3x+7 to 3 you will get 21x=9x+7
> then,
16x-7=9x
> -7=9x-21x
> -7= -12x
negative sign will get cancel
> x=7/12
2007-10-13 06:11:23 · answer #10 · answered by manas n 1 · 0⤊ 0⤋