Respuesta :
Answer:
x = 3
Step-by-step explanation:
This is hard to explain so i'll show you the work



Given expression in the question is,
[tex]\sqrt{x+7}-1=x[/tex]
Solve the expression by using algebraic rules,
[tex]\sqrt{x+7}-1+1=x+1[/tex]
[tex](\sqrt{x+1})^2=(x+1)^2[/tex]
[tex]x+7=(x+1)^2[/tex]
[tex]x+7=x^2+2x+1[/tex]
[tex](x+7)-(x+7)=(x^2+2x+1)-(x+7)[/tex]
[tex]x^2+x-6=0[/tex]
[tex]x^{2}+3x-2x-6=0[/tex]
[tex]x(x+3)-2(x+3)=0[/tex]
[tex](x+3)(x-2)=0[/tex]
Therefore, [tex]x=-3,2[/tex]
For extraneous solutions substitute the values of x in the original expression,
For [tex]x=-3[/tex],
[tex]\sqrt{x+7}-1=x[/tex]
[tex]\sqrt{-3+7}-1=-3[/tex]
[tex]\sqrt{4}-1=-3[/tex]
[tex]2-1=-3[/tex]
[tex]1=-3[/tex]
Therefore, [tex]x=-3[/tex] is an extraneous solution.
For [tex]x=2[/tex],
[tex]\sqrt{2+7}-1=2[/tex]
[tex]3-1=2[/tex]
[tex]2=2[/tex]
Therefore, [tex]x=2[/tex] is the solution.
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