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 Question from Deborah, a student: 2(v+10)<18

Hi Deborah,

I am going to solve a similar problem.

Solve for x if 2(4 - 3x) < 14.

You can solve this type of inequality just as you would solve an equality with one extra condition. If you multiply or divide both sides by a negative number you must reverse the direction of the inequality. Here's what I mean.

Solve for x if 2(4 - 3x) = 14.

Solution.

 2(4 - 3x) = 14 divide both sides by 2 4 - 3x = 7 subtract 4 from each side -3x = 3 divide both sides by -3 x = -1

Now the inequality.

Solve for x if 2(4 - 3x) < 14.

Solution.

 2(4 - 3x) < 14 divide both sides by 2 4 - 3x < 7 subtract 4 from each side -3x < 3 divide both sides by -3 x > -1

The steps are the same except that the equal sign is replaced by the less than sign and at the last step, since I divided by a negative number I reversed the less than sign and got a greater than sign.

Now try your problem,
Penny

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