Question

x
$x { }^{2} - 8x - 16 = 0$

Answer 1

x^2 - 8x - 16 = 0

=> x^2 - 4x - 4x - 16 = 0

=> x(x-4) - 4(x-4) = 0

=> (x-4)(x-4) = 0

x = 4

Answer 2

ques. find "x"

given: 
 x² - 8x - 16 = 0
--> x² - 4x - 4x - 16 = 0
--> x(x-4) - 4(x-4) = 0
--> (x-4)(x-4)=0 ("x" cross the another "x" no value of 0)
--> 4.

hence the answer is 4.

thanks