How do you solve by completing the square: x^2 – 6x -7 = 0?
1 Answer
Mar 30, 2015
Roots are x=7; -1
Rewrite the equation as x^2 -6x+9 -9-7=0
x^2 -6x+9 =16
(x-3)^2 =16
x-3= 4, -4
x= 7; -1
Concept: Half the coefficient of term with x. It would be -3 here. Square it. It would be 9. Now add 9 and subtract 9 as shown above for completing the square.
