Question 968605
{{{ x^2 - 8x + 7 = 0 }}}
You can complete the square
{{{ X^2 - 8x + ( 8/2 )^2 = -7 + ( 8/2 )^2 }}}
{{{ x^2 - 8x + 16 = -7 + 16 }}}
{{{ ( x - 4 )^2 = 3^2 }}}
Take the square root of both sides
{{{ x - 4 = 3 }}}
{{{ x = 7 }}}
and, taking the negative square root,
{{{ x - 4 = -3 }}}
{{{ x = 1 }}}