Question

solve the equation by completing the square. round to the nearest hundredth if necessary??
x^2 - 6x = -8

Answer 1

take half of the x coefficient -6 to get -6/2 = -3

then square this to get (-3)^2 = 9

Answer 2

now add the result of 9 to both sides

x^2 - 6x = -8

x^2 - 6x + 9 = -8+9

x^2 - 6x + 9 = 1

what's next?

Answer 3

Above equation can be rewritten as
x^2-6x+8=0
(Now u need to break 8 such that the multiples have their sum =-6 & product =8
Find out factors of 8 for that & try various combinations)
Here -4*-2=+8
& -4+-2=-6
Hence Above equation can be written as
Hence -2 & -4 are the roots of equation
so (x=2 & x=4) are the required solution.
Since (x-2)(x-4)=0 (Product is zero if either one or both of them is zero)

Alternatively u can always use this formula for solving such equations:
ax^2+bx+c=0
then roots are
x=[-b+Squrt(b^2-4ac)]/2a & [-b-sqrt(b^2-4ac)]/2a

This should help