2006-11-21 07:45:18 · 17 answers · asked by jaynaee1990 1 in Science & Mathematics ➔ Mathematics
3x-12=4x-20
20-12=4x-3x
8=x
2006-11-21 07:48:17 · answer #1 · answered by ~~kelly~~ 6 · 3⤊ 0⤋
3 ( x - 4 ) = 4 ( x - 5 )
3 x - 12 = 4 x - 20
-12 = x - 20
8 = x
x = 8 or 8 = x
2006-11-21 14:24:51 · answer #2 · answered by Angels Eyes 2 · 0⤊ 0⤋
3(x - 4) = 4(x - 5)
3x - 12 = 4x - 20 (Subtract 3x from, and add 20 to both sides)
x = 8
Check:
3((8) - 4) = 4((8) - 5)
3(4) = 4(3)
12 = 12
QED
2006-11-21 08:15:46 · answer #3 · answered by CSUFGrad2006 5 · 1⤊ 0⤋
x=8
2006-11-21 07:48:34 · answer #4 · answered by Dupinder jeet kaur k 2 · 1⤊ 0⤋
Simple...
3(x-4) = 3x - 12
4(x-5)= 4x - 20
4x- 20 = 3x - 12
add
-3x = -3x
x - 20 = -12
add
20 = 20
x = 8
so,
3(8-4) = 3(4) = 12
4(8-5) = 4(3) = 12
Good luck!
2006-11-21 07:51:53 · answer #5 · answered by alrivera_1 4 · 1⤊ 0⤋
3(x -4) = 4(x -5) distribute 3 & 4
3x-12=4x-20 subtract 3x from each side
-12=x-20 add 20 to each side
8=x or
x=8
2006-11-21 07:57:59 · answer #6 · answered by yupchagee 7 · 1⤊ 0⤋
3(x-4) = 4(x-5)
3x-12 = 4x-20
-4x+3x = -20+12 =
-x = -8 or x = 8
Just divide by negative one to get the positive answer.
2006-11-21 07:53:08 · answer #7 · answered by Boomer0283 2 · 1⤊ 0⤋
4x-3x=20-12
x=8
2006-11-21 08:07:46 · answer #8 · answered by kula o 2 · 1⤊ 0⤋
3x-12 = 4x-20
add 20 to each side
3x + 8 = 4x
subtract 3x from each side
8 = x
2006-11-21 08:31:15 · answer #9 · answered by unan1m0us 5 · 1⤊ 0⤋
3(x -4) = 4(x -5)
3x - 12 = 4x - 20
3x = 4x - 20 + 12
3x = 4x - 8
3x - 4x = -8
-x = -8
x = 8
2006-11-21 14:52:20 · answer #10 · answered by Akilesh - Internet Undertaker 7 · 0⤊ 1⤋
3x-12=4x-20
-x-12=-20
-x=-8
x=8
Check:
3(8-4)=4(8-5)
3(4)=4(3)
12=12
2006-11-21 07:51:01 · answer #11 · answered by Anonymous · 0⤊ 0⤋