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:

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

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

$2 = f$

$f = 2$

How do you solve 4-7f = f - 124-7f = f - 12?