How do you solve #28 = 3 m - 7 m#?

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Answer 1 · 2016-10-12T23:58:30

#m = -7#

Combine like terms:

#28 = color(red)(3m-7m)#

#28 = color(red)((3-7)m)#

#28 = color(red)(-4m)#

Isolate #m# by dividing by its coefficient:

#28 = color(red)(-4)m#

#28/color(red)(-4) = (-4m)/(color(red)(-4))#

#(-7xxcancel(-4))/cancel(-4) = (cancel(-4)m)/cancel(-4)#

#-7 = m#

Check the result:

#3(-7) - 7(-7) = -21 - (-49) = -21 + 49 = 28#

As the result holds, we have our final answer:

#m = -7#