How do you solve #-5( 2+ 7r ) = 130#?

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Answer 1 · 2017-05-27T20:44:47

See a solution process below:

First, divide each side of the equation by #color(red)(-5)# to eliminate the need for parenthesis while keeping the equation balanced:

#(-5(2 + 7r))/color(red)(-5) = 130/color(red)(-5)#

#(color(red)(cancel(color(black)(-5)))(2 + 7r))/cancel(color(red)(-5)) = -26#

#2 + 7r = -26#

Next, subtract #color(red)(2)# from each side of the equation to isolate the #r# term while keeping the equation balanced:

#-color(red)(2) + 2 + 7r = -color(red)(2) - 26#

#0 + 7r = -28#

#7r = -28#

Now, divide each side of the equation by #color(red)(7)# to solve for #r# while keeping the equation balanced:

#(7r)/color(red)(7) = -28/color(red)(7)#

#(color(red)(cancel(color(black)(7)))r)/cancel(color(red)(7)) = -4#

#r = -4#