Sunday, November 6, 2011

(6x-8) - (5x+9) =3solve for x

grumpybear -- You know how to do the distributive property I would assume . . so you will use it to get rid of the paratheses in the problem.


Is there anything in front of the first set of ()'s?  This would make them a little unneccessary . . so just drop them. 


Now in front of the second set is only a - . . .think of this as a -1 (because there is always an invisible 1 if there is nothing in that spot, right?)  So, distribute the -1 into the second set of ()'s.  Now you will have . . .


6x - 8 - 5x - 9 = 3  -->  {-1(5x) + -1(9) = -5x - 9}


from here, combine like terms (x's with other x's & #'s with other #'s) on the same side of the equal sign.


6x - 5x = 1x or just x (there's the invisible 1 again)


-8 - 9 = -17


so . .


x - 17 = 3      This is looking a little easier to handle right!


   +17     +17    add 17 to both sides to cancel it from the x


x        =  20


Distributing the negative problems (like this one) can be a little tricky.  Remember to check your answers to make sure you are right . . .use your calculator to make it quick and easy to check . . .


(6*20 - 8) - (5*20 + 9) = ?


(112) - (109) = 3

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