How do you solve #(2x - 3) + ( 3x - 12) = 45#?

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Answer 1 · 2016-09-22T18:33:34

#x=12#

#color(blue)("Using first principles")#

The plus in front of the right hand bracket means that when the brackets are removed the signs inside the bracket do not change.

Thus the given equation is the same as: #" "2x-3+3x-12=45#

#2x+3x-3-12=45#

#5x-15=45#

Add #color(blue)(15)# to both sides

#color(brown)(5x-15color(blue)(+15)=45color(blue)(+15)#

#5x+0=60#

Divide both sides by #color(blue)(5)#

#color(brown)(5/(color(blue)(5)) xx x=60/(color(blue)(5)))#

#x=12#