Im having a little trouble doing it, could anyone help me? Argh, i mean i know all the steps but this tricks me all the time lol
for Example:
3x-7=4x-2
+7 +7
3x=4x-9
-4 -4
-1x=-9
would it be x=-9 or x=9?
2007-11-01 08:27:30 · 10 answers · asked by FinalThought182 4 in Science & Mathematics ➔ Mathematics
bc it cant be a -x=-9 right? the variable has to be positive?
2007-11-01 08:30:28 · update #1
i mean, i know how to do it, but in the end if it ends up to be a -x=-5 would it end up being positive?
2007-11-01 08:33:24 · update #2
Tip: any term can be moved from one side of the equal sign to the other side as long as you change the sign of the term.
3x-7 =4x-2
-7+2 = 4x-3x
-5 = x
Isn't this simpler? It's called transposition or transposing.
Try it. It will save you lot's of time, and help to keep you from making errors. (Like coming up with -9 instaed of -5)
2007-11-01 08:40:30 · answer #1 · answered by ironduke8159 7 · 0⤊ 0⤋
Well for 1 thing, when you did +7 to the right, it makes it 4x+5, not 4x-9. So you would end up with -1x=5.
it would be x=-5, because you divide both sides by -1.
2007-11-01 08:31:53 · answer #2 · answered by mathguru 3 · 0⤊ 0⤋
3x - 7 = 4x - 2
+ 7 on both sides
3x - 7 + 7 = 4x - 2 + 7
3x = 4x + 5
- 4x on both sides
3x - 4x = 4x - 4x +5
-x = 5
Multiply -1 to both sides
-x * -1 = 5 * -1
x = -5
Hope that helps
2007-11-01 08:32:11 · answer #3 · answered by gmat g 3 · 0⤊ 0⤋
You erred in the +7 +7 step. The result is 3x = 4x + 5. Now subtract 4x from both sides [-4x - 4x in your notation], and we get -x = 5, or x = -5
2007-11-01 08:36:21 · answer #4 · answered by John V 6 · 0⤊ 0⤋
3x-7 = 4x-2
you add positive 7 to both sides (+7-2=5, not -9)
3x= 4x+5
you subtract 4x from both sides
-1x=5
you divide everything by negative one
and get
x=-5
i would of move the 2 over and not the 7 first because then you move the 3x to the other side and dont have to divide by negative one.
3x-7=4x-2
3x-5=4x
-5=x
hope that helps
2007-11-01 08:34:18 · answer #5 · answered by Jennifer 3 · 0⤊ 0⤋
3x - 7 = 4x -2
+7 +7
3x = 4x + 5
-4x -4x
-x = 5
x= -5
the variable should not be negative BUT the VALUE of the variable CAN be negative
2007-11-01 08:35:34 · answer #6 · answered by Sheep Herder 3 · 0⤊ 0⤋
As Summer Bre noted, -2 + 7 = 5, not -9.
As to your additional detail, yes, you can have -x = -9. You just wouldn't leave it in that form for your final answer. You'd multiply both sides by -1 to get x = 9.
2007-11-01 08:36:32 · answer #7 · answered by Bob G 6 · 0⤊ 0⤋
in my opinion,use BIDMAS: Brackets Indices branch Multiplication upload Subtract that's a mnemonic for order in which mathematical calculations are executed. First,do the sum of the numbers contained in the brackets: a million+2=3 Secondly,you would use branch:6÷2=3 0.33, as you presently have 2 numbers next to one yet another like this: 33 you would multiply them jointly: 3x3=9 And there, now you've your answer: 9 desire it is functional and comprehensible for you :)
2016-10-23 05:39:59 · answer #8 · answered by favreau 3 · 0⤊ 0⤋
x=-5
2007-11-01 08:33:27 · answer #9 · answered by Anonymous · 0⤊ 1⤋
3x-7=4x-2
3x=4x+5
-1x=5
x=-5
2007-11-01 08:31:28 · answer #10 · answered by Summer Bre 2 · 0⤊ 0⤋