Answer:
[tex]\large\boxed{d)\ x=-5\pm\sqrt{31}}[/tex]
Step-by-step explanation:
[tex]x^2+10x=6\\\\x^2+2(x)(5)=6\qquad\text{add}\ 5^2\ \text{to both sides}\\\\x^2+2(x)(5)+5^2=6+5^2\qquad\text{use}\ (a+b)^2=a^2+2ab+b^2\\\\(x+5)^2=6+25\\\\(x+5)^2=31\iff x+5=\pm\sqrt{31}\qquad\text{subtract 5 from both sides}\\\\x=-5\pm\sqrt{31}[/tex]
