x^2 + 10x + 25 = (x+5)^2
(x+5)^2 = 18
(x+5) = +/-sqrt(18)
Can you take it from here?
=^._.^=
First we have to turn the equation to a standard quadratic equation: we get
\(x^2 + 10x + 7 = 0\)
Now we can apply the quadratic formula. x = \(-b {+\over} \sqrt{b^2 - 4ac}\over2a\) where a is the coefficient of x^2, b is the coefficient of x, and c is the constant.
Plugging in the values, we get x = \(-10 {+\over} 6\sqrt{2}\over2\) for our two solutions of x.
Since the problem is asking for the smaller value, we take the subtraction operation in the equation above, getting:
x = \(-5 - 3\sqrt{2}\)