please solve for x
2007-09-28 14:44:03 · 5 answers · asked by kyle p 1 in Science & Mathematics ➔ Mathematics
3 = 12x² + 48 x
4x² + 16x - 1 = 0
x = [- 16 ± √(16 ² + 16) ] / 8
x = [- 16 ± √ 272 ] / 8
x = [- 16 ± 4√17] / 8
x = - 2 ± (1/2)√17
2007-09-28 21:12:50 · answer #1 · answered by Como 7 · 0⤊ 0⤋
Cross multiply..so you get
3=6x(2x+8)
3=12x^2+48x
Now move 3 to the other side
12x^2+48x-3=0
Factor out the 3
3(4x^2+16x-1)=0
Now just solve for x.
2007-09-28 21:52:41 · answer #2 · answered by mrr86 5 · 0⤊ 0⤋
Ok so 3(2x+8)=6x
PEMDAS
2+8=10
then, you bring the 3 down and times that by 10.
the you do 6x divided by 30=5
so x=5
2007-09-28 22:43:14 · answer #3 · answered by Anonymous · 0⤊ 0⤋
6x(2x+8) = 3
or 12x^2 + 48x -3 = 0 or or 4x^2 + 16x -1 = 0
Can you solve from here?
continue to get, 4(x+2)^2 = 17
or x = -2 + sqrt(17)/2, -2 - sqrt(17)/2
2007-09-28 21:56:53 · answer #4 · answered by Siddhartha Basu 4 · 0⤊ 0⤋
[3/(2x+8)]*(2x+8)=6x*(2x+8)
[3=12x^2+48x]/12
1/4=x^2+4x
1/4+4=x^2+4x+4
17/4=(x+2)^2
(+or- square root of 17)/2=x+2
x= -2 +or- [(the square root of 17)/ 2]
2007-09-28 21:58:19 · answer #5 · answered by Anonymous · 0⤊ 0⤋