How do you solve #3[ 2x - ( x + 9) ] = 5( x - 3)#?

2 Answers
Suren Abreu
Oct 22, 2016

#x=-6#

Explanation:

#3[2x-(x+9)]=5(x-3)#

Open the curved brackets and simplify.

#3[2x-x-9]=5x-15#

#3[x-9]=5x-15#

Now open the square brackets and simplify.

#3x-27=5x-15#

Subtract #3x# from both sides.

#-27=2x-15#

Add #15# to both sides.

#-27+15=2x#

#-12=2x#

Divide both sides by #2#.

#-6=x# or #x=-6#

Léonie R.
Oct 22, 2016

first solve the brackets ->
3 ( 2x -x -9) = 5x - 15
6x - 3x - 27 = 5x - 15
3x - 27 = 5x - 15 -> pull over -27 and 5x
-2x = 12 -> divided by -2
x = -6

Explanation:

always try to solve the brackets in the brackets first.
first i tok away the brackets on the left with simply having to change + to a -
then i think you can see what i did there. you can also calculate the 2x-x-9 so it would be (x - 9) and then take away those brackets and then calculate 3 ( x - 9 ). you'll get the same result anyways.

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