28 Calculați media aritmetică a numerelor x şi y, unde: a x = 2√27+3√12-5√48+2√147; b x= 2√√63-√252+3√28-√√175; cx= 4√27+5√72-7√32-6√75; d x = 5√700-2√200+3√567+4√50; y = 4√12-3√75+11√108; y=√18+√√847-2√112-5√8; y=3√128 +6√108-8√18-10√27; y = 2√162 +11√√28-9√8-3√63 VA ROG MULT E URGENT!!!! DAU COROANA!!!!!