Question

How do you solve `x^2+8x-10=0` by completing the square?

Answer 1

`x=-4+-sqrt26`

Explanation:

`"using the method of "color(blue)"completing the square"`

`• " the coefficient of the "x^2" term must be 1 which it is"`

`• " add/subtract "(1/2" coefficient of the x-term")^2" to"`
`x^2+8x`

`x^2+2(4)xcolor(red)(+16)color(red)(-16)-10=0`

`rArr(x+4)^2-26=0`

`rArr(x+4)^2=26`

`color(blue)"take the square root of both sides"`

`rArrx+4=+-sqrt26larrcolor(blue)"note plus or minus"`

`"subtract 4 from both sides"`

`rArrx=-4+-sqrt26larrcolor(red)"exact solutions"`