>>896
(2√3-5)^2+10(2√3-5)+25
=(3√3-5-√3)^2+10(3√3-5-√3)+25
=(3√3)^2+(-5)^2+(-√3)^2+2(3√3)(-5)+2(-5)(-√3)+2(-√3)(3√3)+10(3√3)+10(-5)+10(-√3)+25
=27+25+9-30√3+10√3-12+30√3-50-10√3+25
=51-20√3-12+30√3-25-10√3
=51-37=12