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

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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#