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22 votes
Solve the inequalities please

Solve the inequalities please-example-1
User Bruno Unna
by
6.5k points

2 Answers

14 votes

#1

  • 3x+12-6x≤-9
  • -3x+12≤-9
  • -3x≤-21
  • 3x≥21
  • x≥7

#2

  • x+5x-6<12
  • 6x<18
  • x<3

#3

  • 5(x+8)-7≤23
  • 5x+40≤30
  • 5x≤-10
  • x≤-2

#4

  • 4x-6≥6x-20
  • -2x≥-14
  • x≤7
User MarkAlanFrank
by
7.1k points
4 votes


\huge\text{Answer:}

Inequality number 1: x≥7

Inequality number 2: x<3

Inequality number 3: x≤-2

Inequality number 4: x≤7


\huge\text{Solution:}

1. 3x+12-6x≤-9

3x-6x+12≤-9

Subtract the x's:

-3x+12≤-9

-3x≤-9-12

-3x≤-21

3x≥21

x≥7

2. x+5x-6<12

6x-6<12

Move 6 to the right, using the
\bold{\underline{opposite ~operation}}:

6x<12+6

6x<18

Now, divide both sides by 6:

x<3

3. 5(x+8)-7≤23

Use the Distributive Property:

5x+40-7≤23

5x+33≤23

5x≤23-33

5x≤-10

x≤-2

4. 4x-6≥6x-20

4x-6x≥-20+6

-2x≥-14

2x≤14

x≤7

___________________________

Note:

If we divide both sides of the inequality by a negative variable, we flip the inequality sign.

___________________________

Hope you find it helpful.

Feel free to ask if you have any doubts.

User Larissa
by
6.4k points
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