Question 865073
The idea is to isolate x. We do this by taking the square root of both sides, simplifying and adding 20 to both sides



{{{(x-20)^2 = 27}}}



{{{x-20 = ""+-sqrt(27)}}} Don't forget about the plus/minus



{{{x-20 = sqrt(27)}}} or {{{x-20 = -sqrt(27)}}} Break up the plus/minus



{{{x-20 = sqrt(9*3)}}} or {{{x-20 = -sqrt(9*3)}}}



{{{x-20 = sqrt(9)*sqrt(3)}}} or {{{x-20 = -sqrt(9)*sqrt(3)}}}



{{{x-20 = 3*sqrt(3)}}} or {{{x-20 = -3*sqrt(3)}}}



{{{x = 20+3*sqrt(3)}}} or {{{x = 20-3*sqrt(3)}}}



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Final Answer:



{{{x = 20+3*sqrt(3)}}} or {{{x = 20-3*sqrt(3)}}}



These answers are exact.