Answer:
[tex]x =-5\ - \sqrt{8}[/tex]
Step-by-step explanation:
Given
[tex]x^2 + 10x + 25 = 8[/tex]
Required
Find the smallest value of x
[tex]x^2 + 10x + 25 = 8[/tex]
Expand the expression on the right hand side
[tex]x^2 + 5x + 5x + 25 = 8[/tex]
Factorize
[tex]x(x+5)+5(x+5) = 8[/tex]
[tex](x+5)(x+5) = 8[/tex]
[tex](x+5)^2 = 8[/tex]
Take Square root of both sides
[tex]\sqrt{(x+5)^2} = \±\sqrt{8}[/tex]
[tex](x+5) = \±\sqrt{8}[/tex]
Remove bracket
[tex]x+5 = \±\sqrt{8}[/tex]
Subtract 5 from both sides
[tex]x+5-5 =-5\± \sqrt{8}[/tex]
[tex]x =-5\± \sqrt{8}[/tex]
[tex]x =-5\ + \sqrt{8}[/tex] or [tex]x =-5\ - \sqrt{8}[/tex]
Comparing both values of x;
The smallest value of x is
[tex]x =-5\ - \sqrt{8}[/tex]
