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а.
 0.4 √80  √5 + 25 √0.45  √5 -9 √45 :√5 = 0.4 √16+ 25√0.09 - 9√4 =0.4 *4+ 25*0.3 - 9*2=
1.6+7.5-18= -8.9
б.
( √(0.2³)² *√((-3)² )² * √((-5)²)²   )    1*2  = 0.2³ *9 * 25 2 = 0.1 * 9 * 25 = 22.5