Solve sqrt (x+ a) = x −7 when a=-1

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Discussion Overview

The discussion revolves around solving the equation sqrt(x + a) = x - 7 with a set to -1. Participants explore potential solutions and their validity through substitution into the original equation.

Discussion Character

  • Homework-related, Mathematical reasoning, Debate/contested

Main Points Raised

  • Some participants propose potential solutions to the equation, including {5}, {10}, {5, 10}, and "No solution (5, 10)".
  • One participant asks for verification by substituting each proposed solution back into the original equation.
  • Another participant attempts to validate the solution by substituting x = 5 into the equation, leading to a contradiction.
  • There is a request for clarification on what "works out" means in the context of the discussion.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the correct solution set, and there is disagreement regarding the validity of the proposed solutions.

Contextual Notes

There are unresolved mathematical steps regarding the verification of proposed solutions and the implications of the substitutions made.

rebo1984
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Hi,

If a = -1, what is the solution set of the equation sqrt (x+ a) = x −7

{5}
{10}
{5, 10}
No solution(5,10) correct?

Thanks
 
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rebo1984 said:
Hi,

If a = -1, what is the solution set of the equation sqrt (x+ a) = x −7

{5}
{10}
{5, 10}
No solution(5,10) correct?

Thanks

What do you get when you substitute each potential solution into the original equation?
 
MarkFL said:
What do you get when you substitute each potential solution into the original equation?

It works out.
 
rebo1984 said:
It works out.

Let's try \(x=5\):

$$\sqrt{5-1}=5-7$$

$$2=-2$$

Is this true?
 
rebo1984 said:
It works out.
What "works out"? Which answer did you get?
 

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