How do you solve #0.7(2m-5)>=21.7#?

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Answer 1 · 2016-10-17T07:58:01

#m >= 18#

Treat an inequality in the same way as an equation unless you multiply or divide by a negative, which does not apply in this case.

We could start by multiplying #0.7# into the bracket, but we eventually want the #m# on its own, so rather start by dividing both sides by #0.7#

#0.7/0.7(2m-5) >= color(red)(21.7/0.7)#

[Recall: dividing by a decimal:#color(red)(21.7/0.7= (21.7xx10)/(0.7xx10) = 217/7)#]

#2m - 5 >= color(red)(217/7)" "larr +5# to both sides

#2m >= 31+5#

#2m >= 36#

#m >= 18#