How do you solve #9x - 12 = 5x + 8#?

1 Answer
smendyka
Apr 10, 2017

See the entire solution process below:

Explanation:

First, add #color(red)(12)# and subtract #color(blue)(5x)# from each side of the equation to isolate the #x# term while keeping the equation balanced:

#9x - 12 + color(red)(12) - color(blue)(5x) = 5x + 8 + color(red)(12) - color(blue)(5x)#

#9x - color(blue)(5x) - 12 + color(red)(12) = 5x - color(blue)(5x) + 8 + color(red)(12)#

#(9 - color(blue)(5))x - 0 = 0 + 20#

#4x = 20#

Now, divide each side of the equation by #color(red)(4)# to solve for #x# while keeping the equation balanced:

#(4x)/color(red)(4) = 20/color(red)(4)#

#(color(red)(cancel(color(black)(4)))x)/cancel(color(red)(4)) = 5#

#x = 5#

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