Basic solving for variable question.

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In summary, the equation is linear, so there can be only one solution (x = 1/2). Are you sure you have written the equation correctly?Yes, I'm sure I wrote the equation correctly.
  • #1
davie08
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Homework Statement


if (4x+1) + 6 = 9, then x=?


Homework Equations





The Attempt at a Solution



the answer is -1 and 1/2, but how could -1 work wouldn't that make the answer 3 instead of 9.
 
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  • #2
davie08 said:

Homework Statement


if (4x+1) + 6 = 9, then x=?


Homework Equations





The Attempt at a Solution



the answer is -1 and 1/2, but how could -1 work wouldn't that make the answer 3 instead of 9.
The equation is linear, so there can be only one solution (x = 1/2). Are you sure you have written the equation correctly?
 
  • #3
I meant to say 1/2 or -1 but I feel like they screwed up its a sample placement test with my university.
 
  • #4
The only solution to the equation you gave is x = 1/2.
 
  • #5
okay thanks I've never had a question answered so fast in a forum before, I was trying out this forum compared to another one but this forum wins hands down lol.
 
  • #6
davie08 said:

Homework Statement


if (4x+1) + 6 = 9, then x=?

...

the answer is -1 and 1/2, but how could -1 work wouldn't that make the answer 3 instead of 9.
I still think there's a possibility that you didn't copy the question right. If there were absolute value symbols instead of parentheses:
|4x+1| + 6 = 9
... then there would indeed be two solutions, -1 and 1/2.
 
  • #7
eumyang said:
I still think there's a possibility that you didn't copy the question right. If there were absolute value symbols instead of parentheses:
|4x+1| + 6 = 9
... then there would indeed be two solutions, -1 and 1/2.

I'll bet that's it. My thought was that there might be an exponent missing, but that didn't work out.
 
  • #8
eumyang said:
I still think there's a possibility that you didn't copy the question right. If there were absolute value symbols instead of parentheses:
|4x+1| + 6 = 9
... then there would indeed be two solutions, -1 and 1/2.
The other possibility is that some fool, who typed up the exam, replaced "|" with "(" and ")"!
 
  • #9
answer is only 1/2,and i don't know how you got -1.
 
  • #10
shiva999 said:
answer is only 1/2,and i don't know how you got -1.
Did you not read the other replies? The problem is, almost certainly, to solve
|4x+ 1|+ 6= 9, not (4x+ 1)+ 6= 9.
 
  • #11
HallsofIvy said:
Did you not read the other replies? The problem is, almost certainly, to solve
|4x+ 1|+ 6= 9, not (4x+ 1)+ 6= 9.

Either that, or the questioner wrote "and" instead of "or" in a multiple-choice setting (or the OP copied the question incorrectly).

RGV
 

Related to Basic solving for variable question.

What is "basic solving for variable question"?

Basic solving for variable question is a type of mathematical problem where you are given an equation and asked to determine the value of a variable within that equation.

What are the steps for solving a basic solving for variable question?

The steps for solving a basic solving for variable question are:
1. Identify the variable you need to solve for.
2. Use inverse operations to isolate the variable on one side of the equation.
3. Simplify both sides of the equation.
4. Divide both sides by the coefficient of the variable.
5. Check your answer by plugging it back into the original equation.

What are inverse operations?

Inverse operations are mathematical operations that "undo" each other. For example, addition and subtraction are inverse operations, as are multiplication and division. In solving for a variable, you use inverse operations to isolate the variable on one side of the equation.

Can you solve for any variable in a basic solving for variable question?

Yes, as long as the equation contains only one variable and the variable is not in the denominator of a fraction. If the variable is in the denominator, you will need to multiply both sides of the equation by the denominator to eliminate it before solving.

What are some common mistakes to avoid when solving for a variable?

Some common mistakes to avoid when solving for a variable are:
1. Forgetting to perform the same operation on both sides of the equation.
2. Making calculation errors.
3. Forgetting to check your answer by plugging it back into the original equation.
4. Not being careful with negative signs.
5. Not following the order of operations.

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