How do you solve #4-7f = f - 12#?

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Answer 1 · 2017-11-29T01:55:34

See a solution process below:

First, add #color(red)(7f)# and #color(blue)(12)# to each side of the equation to isolate the #f# term while keeping the equation balanced:

#4 - 7f + color(red)(7f) + color(blue)(12) = f - 12 + color(red)(7f) + color(blue)(12)#

#4 + color(blue)(12) - 7f + color(red)(7f) = f + color(red)(7f) - 12 + color(blue)(12)#

#16 - 0 = 1f + color(red)(7f) - 0#

#16 = (1 + color(red)(7))f#

#16 = 8f#

Now, divide each side of the equation by #color(red)(8)# to solve for #f# while keeping the equation balanced:

#16/color(red)(8) = (8f)/color(red)(8)#

#2 = (color(red)(cancel(color(black)(8)))f)/cancel(color(red)(8))#

#2 = f#

#f = 2#