How do you solve #3( x + 9) = - 3( 8x - 7) + 9x#?

2 Answers
Nov 21, 2017

#x=(-1)/3#

Explanation:

#3(x+9)=-3(8x-7)+9x#

Let's start by using the distributive property*

#(3)(x)+(3)(9)=(-3)(8x)+(-3)(-7)+9x#

#3x + 27 = -24x + 21 + 9x#

#3x + 27= -15x + 21#

Subtract #color(red)(27)# from both sides

#3x cancel(+ 27 - color(red)(27))=15x + 21 - color(red)(27)#

#3x = -15x -6#

Add #15x# to both sides

#3x + 15x=cancel(-15x + 15x) -6#

#18x = -6#

Finally, divide both sides by #18#

#(cancel18x)/cancel18 = 6/18#

#x=(-1)/3#

Aug 10, 2018

#x=-1/2#

Explanation:

We can divide both sides by #3# to get

#x+9=-(8x-7)+3x#

Next, we can distribute the negative on the right to get

#x+9=-8x+7+3x#

Combining the #x# terms on the right gives us

#x+9=-5x+7#

Next, add #5x# to both sides to get

#6x+9=7#

Next, subtract #9# from both sides to get

#6x=-3#

Dividing both sides by #6# gives us

#x=-1/2#

Hope this helps!