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11 votes
11 votes
Need help with this homework problem asap please :)

Need help with this homework problem asap please :)-example-1
User Wowonline
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2 Answers

17 votes
17 votes

Answers

Part 1: Solve for the variable

x = 5

Part 2: Is the answer extraneous or not?

5 is as an extraneous solution because when it is plugged back into the equation it results in a false statement

Part 1

Step-By-Step

Part 1:

Isolate x

Subtract 8 to both sides


√(3x+1) + 8 = 4


√(3x+1) = -4

Square both sides of the equation (this will remove the radical sign)

3x + 1 = 16

Subtract 1 to both sides

3x = 15

Divide 3 on both sides

x = 5

Part 2

Define Key Words

What is an extraneous solution?

An extraneous solution is an answer you find when solving for a variable in an equation (x), but when you plug the x back into the equation, the equation results in a false conclusion. This sometimes occurs when you have an equation with a square root.

Step-By-Step

Plug x (5) into the original equation


√(3(5)+1) + 8 = 4

Solve using PEMDAS


√(15+1) + 8 = 4


√(16) + 8 = 4

4 + 8 = 4

12
\\eq 4

This is false, thus 5 is an extraneous solution

Keywords

extraneous solution

User Ckpwong
by
2.9k points
23 votes
23 votes

Answer:

x=5 :)

Explanation:

1) You have to move all the terms which do not include x to the opposite side of the equation so you can solve x for a simple variable.

To do this subtract 8 from both sides!


√(3x+1)+8=4 will become
√(3x+1)=-4

2) Get rid of the square root

To do this square both sides of the equation


√(3x+1) = 3x+1


(-4)^2=16

You will now be left with 3x+1 = 16

3) Get rid of 1 from both sides (subtract)


3x+1-1=3x


16-1=15

You will now be left with 3=15

4) Divide both sides by 3 to get the result for x


3x ÷
3
=x


15 ÷
3=5

You are left with x=5!!!

Hope this helps, have a great day!!!!

User Matthew Wise
by
3.2k points