x^2 -6x =16?

Question

solve by completing the square.

Answer 1

by asking your self what times what will result in negative 16, you begin to develop the combiniations you need to answer the question.

ex. 4 times 4 or 8 times 2
if one of those combinations when added together answers the
-6x part of the equation focus on that combination.... so we choose negative 8 times a positive 2 when solving on the left side of the equation.

ex. (x-8)(x+2)=(xtimesx)+(-8x+2x)-16=0
move the 16 to the other side of the equal sign and that action changes (always) the value from a negative to positive. You have your proof

x^2-6x=16

The answer then is up at the begining where you developed your combinations

(x-8)(x+2)=

plug -8 and positive 2 back into the original equation x^2-6x=16 and both answers will result in the answer 16 on the right side of the equation.

Answer 2

x = 8

Answer 3

x^2 -6x = 16
x^2 - 2.(3).x + (3)^2 =16 +(3)^2 { adding square of 3 on both sides}
(x -3)^2 = 16 +9
(x-3)^2 = 25
(x-3) = +5 or -5
x-3 = 5 or x-3= -5
x=5+3 or x = -5+3
x=8 or x= -2

Answer 4

8 or -2