How do you solve #-[ x - ( - 7x + 4) ] = 6- ( - 4x + 7)#?

2 Answers
Jul 11, 2017

#x=5/12#

Explanation:

First, expand the equation,
#-[x+7x-4]=6+4x-7#
#-x-7x+4=4x-1#

Group similar terms on one side:
x to a side, numbers to a side
#4x+7x+x=4+1#

#12x=5#
#x=5/12#

Jul 11, 2017

#x=5/12#

Explanation:

#"distribute the 'inner' bracket on the left side"#

#-[x+7x-4]=6-(-4x+7)#

#-8x+4=6+4x-7larr" distribute throughout"#

#-8x+4=4x-1larr" simplify right side"#

#"subtract 4x from both sides"#

#-8x-4x+4=cancel(4x)cancel(-4x)-1#

#rArr-12x+4=-1#

#"subtract 4 from both sides"#

#-12xcancel(+4)cancel(-4)=-1-4#

#rArr-12x=-5#

#"divide both sides by - 12"#

#(cancel(-12) x)/cancel(-12)=(-5)/(-12)#

#rArrx=5/12#

#color(blue)"As a check"#

Substitute this value into the equation and if the left side equals the right side then it is the solution.

#-((8xx5/12)-4)=-(40/12-48/12)=8/12=2/3#

#6-((-4xx5/12)+7)=72/12-64/12=8/12=2/3#

#rArrx=5/12" is the solution"#