SOLUTION: 5x-3=13-3x
im having a hard time understanding when youre suppose to add and when your suppose to subtract, also i dont understand how youre suppose to combine variables
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-> SOLUTION: 5x-3=13-3x
im having a hard time understanding when youre suppose to add and when your suppose to subtract, also i dont understand how youre suppose to combine variables
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Question 168843: 5x-3=13-3x
im having a hard time understanding when youre suppose to add and when your suppose to subtract, also i dont understand how youre suppose to combine variables Found 3 solutions by jim_thompson5910, Mathtut, gonzo:Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website! The goal is to get the variable that you want to solve for on one side (in this case "x") and everything else to the other side.
So in this problem, we want to move the "3x" to the left side and the "3" to the right. So to move "3x" to the left side, we need to add 3x to both sides (since it undoes the -3x)
You can put this solution on YOUR website! what you do to one side you must do to the other side of the equals sign. Combine all like terms where you want them trying to move the variables in such a way as to end up with a positve number in front of the variable.
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so you would take the -3x term on the right and add 3x to it thus eliminating it from the right side.......but you must also add 3x to the left so we end up with 5x+3x= 8x on the left.....now lets take care of the constant...to eliminate the -3 on the left we must add 3 to it......and we must add that same amount 3 to the right side making 13+3=16
so we end up with 8x=16 after that process.....now to get x by itself we must divide both sides by 8.....which gives us
You can put this solution on YOUR website! you want to get all the x variables on one side of the equation and you want to get all the constants on the other side of the equation.
you do this by adding or subtracting from both sides of the equation.
here's how it works:
your equation is:
5x - 3 = 13 - 3x
you want to get the 3x from the right side of the equation to the left side of the equation.
you do it by adding 3x to both sides of the equation.
equation becomes:
5x - 3 + 3x = 13 - 3x + 3x
you can see that the - 3x and + 3x on the right side of the equation cancel out so the equation becomes:
5x - 3 + 3x = 13
when you combine like terms, the equation becomes:
8x - 3 = 13
now you want to move the -3 over to the right side of the equation.
you do it by adding 3 to both sides of the equation.
8x - 3 + 3 = 13 + 3
when you combine like terms, the -3 and + 3 on the left side of the equation cancel out and you get:
8x = 13 + 3
which becomes:
8x = 16
you divide both sides of the equation by 8 to get
x = 16/8 = 2
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you substitute 2 for x in your original equation:
5x - 3 = 13 - 3x
becomes:
5*2 - 3 = 13 - 3*2
which becomes:
10 - 3 = 13 - 6
which becomes:
7 = 7
since this is true, the value of x = 2 is good.
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when you combine like terms, you are adding together all the terms that have the same variable.
5x + 6x + 3x = 14x
they are like terms because they are all multiples of x.
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similarly, if you have:
5x^2 - 3x + 2x^3 + 15x - 20x^2
you would combine like terms as follows:
5x^2 - 20x^2 = -15x^2
-3x + 15x = 12x
2x^3 doesn't have anything to combine with.
your final combined terms are:
2x^3 - 15x^2 + 12x
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