(see the question for the problem) We're supposed to find what x is. My friend and I can't figure out whether it would be 13 or -13.
Please help! Thanks in advance.
2007-10-17 16:31:29 · 10 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
4x + 7 = 5x - 6
7 + 6 = 5x - 4x
x = 13
2007-10-18 19:37:08 · answer #1 · answered by Como 7 · 0⤊ 0⤋
6x + 7 -2x = 2 + 5x - 9
Start with your answer and plug in 13 to test.
6(13) + 7 - 2(13) = 2 + 5(13) -9
78 + 7 - 26 = 2 + 65 - 9
85 -26 = 67 - 9
59 = 58
Now try your friend's answer
6x + 7 -2x = 2 + 5x - 9
6(-13) + 7 - 2(-13) = 2 + 5(-13) -9
-78 + 7 + 26 = 2 - 65 - 9
-78 + 33 = 2 - 74
-45 = - 72
That's wrong too.
6x + 7 -2x = 2 + 5x - 9
6x - 2x - 5x = 2 - 9 - 7
- x = -14
or x = 14
You can check this by plugging into the equation
6x + 7 -2x = 2 + 5x - 9
6(14) + 7 - 2(14) = 2 + 5(14) -9
84 + 7 - 28 = 2 + 70 - 9
91-28 = 72-9
63 = 63
2007-10-17 17:03:47 · answer #2 · answered by Anonymous · 0⤊ 0⤋
13
2007-10-17 19:15:47 · answer #3 · answered by f312ry 1 · 0⤊ 0⤋
6x - 2x +7 = 3-9 +5x
Combine like terms:
(6x-2x) +7 = (3-9) + 5x
4x + 7 = -6 +5x
Now add 6 to both sides and subtract 4x from both sides:
4x-4x + 7 + 6 = -6+6 -4x +5x
13 = x
So x = 13...
2007-10-17 16:35:59 · answer #4 · answered by sayamiam 6 · 0⤊ 0⤋
6x+7-2x=3+5x-9
4x+7= -6+5x
4x+13=5x
13=x
2007-10-17 16:35:22 · answer #5 · answered by ?? 1 · 0⤊ 0⤋
6x + 7 - 2x = 3 + 5x -9
6x -2x - 5x = 3 -9 -7
-x = -13
x = -13/ -1
x = 13
2007-10-17 16:36:31 · answer #6 · answered by kitten 4 · 0⤊ 0⤋
4x+7 = 5x -6
4x+13 = 5x
13 = x
its positive 13
2007-10-17 16:35:33 · answer #7 · answered by science_guy 5 · 0⤊ 0⤋
SIMPLE X=13
2007-10-17 16:35:37 · answer #8 · answered by Jairo 1 · 0⤊ 1⤋
easy, x=125
2007-10-17 16:39:38 · answer #9 · answered by bigT 3 · 0⤊ 0⤋
positive i checked it on my graphing calculator
2007-10-17 16:39:42 · answer #10 · answered by DINO_GOES_RAWER 3 · 0⤊ 0⤋