Question 110344
{{{(x - 5)^2 = 7}}}
take the square root of both sides
Note that the square root can be positive or negative
{{{x - 5 = sqrt(7)}}}
{{{x - 5 = - sqrt(7)}}} both of these are true
Now solve for x
{{{x - 5 = sqrt(7)}}}
{{{x = 5 + sqrt(7)}}} answer
and
{{{x - 5 = - sqrt(7)}}}
{{{x = 5 - sqrt(7)}}} answer
Now check both answers
{{{(5 + sqrt(7) - 5)^2 = 7}}}
{{{(+ sqrt(7))^2 = 7}}}
{{{7 = 7}}}
OK
{{{(5 - sqrt(7) - 5)^2 = 7}}}
{{{(- sqrt(7))^2 = 7}}}
7 = 7
OK