How do you solve by completing the square $a^2+ 8a + 11 = 0$ ?

Question

2507 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-04-30T18:27:35

$a=4+sqrt5, 4-sqrt5$

$a^2+8a+11=(a+4)^2-16+11=(a+4)^2-5$

Checking:

$(a+4)(a+4)=a^2+8x+16-5=a^2+8x+11$

Solve:

$(a-4)^2-5=0$

$(a-4)^2=5$

$a-4=pmsqrt5$

$a=4pmsqrt5$

How do you solve by completing the square a^2+ 8a + 11 = 0a^2+ 8a + 11 = 0?