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What is the solution set of the equation |2x+3|=7 in the set of rational numbers?

A, {4,-10}

B, {5,-2}

C. {4,5}

D. {-5,2}



User Robalb
by
4.0k points

2 Answers

1 vote

Answer: D. {-5, 2}

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Work Shown:

|2x+3| = 7 means either 2x+3 = 7 or 2x+3 = -7

Solve each for x

2x+3 = 7

2x = 7-3

2x = 4

x = 4/2

x = 2 is one solution

Repeat for the other equation

2x+3 = -7

2x = -7-3

2x = -10

x = -10/2

x = -5 is the other solution

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Each solution can be checked by plugging it back into the original equation and simplifying. You should get the same number on both sides

For instance, checking x = -5 leads to

|2x+3| = 7

|2(-5)+3| = 7

|-10+3| = 7

|-7| = 7

7 = 7

Which confirms x = -5. I'll let you check x = 2.

User Shereen
by
4.2k points
1 vote

Answer:

d

Explanation:

-10=-5*2; 4=2*2

l-10+3l= 7; l4+3l=7

User Carlos H
by
3.7k points