Respuesta :
Answer:
x = 2 and x = -3
Step-by-step explanation:
We need to find the value of x in the below expression.
[tex]\sqrt{x+7} -1=x[/tex]
Adding 1 to both sides,
[tex]\sqrt{x+7} -1+1=x+1\\\\\sqrt{x+7}=x+1[/tex]
Squaring both sides,
[tex]x+7=(x+1)^2\\\\x+7=x^2+1+2x\\\\x^2+1+2x-x-7=0\\\\x^2+x-6=0\\\\x=2\ and\ -3[/tex]
Hence, this is the required solution.
[tex]\bf\huge x=2 [/tex]
Step-by-step explanation:
Given that :
- [tex]\sqrt{x+7} -1=x\\[/tex]
to find :
- [tex]\sqrt{x+7} -1=x\\[/tex]
explanation :
⟼ [tex]\sqrt{x+7} -1=x\\[/tex]
⟼ √x + 7 = x + 1
⟼ x + 7 = x² + 2x + 1
⟼ x + 7 - x² - 2x - 1 = 0
⟼ -x + 6 -x² = 0
⟼ x² + x - 6 = 0
⟼ (x-2) (x+3) = 0
⟼ x = 2 and x = -3
When x = -3 the original equation √x+7-1 = x does not hold true. We will drop x = -3 from the solution set.
Therefore,
⟼ x = 2.
verification :
⟼ let take x = 2
⟼ [tex]\sqrt{x+7} -1=x\\[/tex]
⟼ √2+7 - 1 = 2
⟼ √9 - 1 = 2
⟼ 3 - 1 = 2
⟼ 2 = 2