## Intermediate Algebra for College Students (7th Edition)

$x = 2\sqrt {7}-5$ or $x=-2\sqrt {7}-5$
$x^2 + 10x - 3 = 0$ Add $3$ to both sides. $x^2 + 10x - 3+3 = 0+3$ $x^2 + 10x = 3$ The coefficient of the $x$-term is $10$. Half of $10$ is $5$, and $5^2$ is $25$. Thus, add $25$ to both sides to complete the square. $x^2 + 10x +25= 3+25$ $(x+5)^2=±\sqrt {28}$ $x+5= ±4\sqrt {7}$ Subtract $5$ to both sides. $x+5-5= ±2\sqrt {7}-5$ $x= ±2\sqrt {7}-5$ $x = 2\sqrt {7}-5$ or $x=-2\sqrt {7}-5$