👤

se dau relațiile a×b=21 c×c=81si b×b=c


Răspuns :

a×b=21

c×c=81

b×b=c

c×c=9×9=81

c=9

b×b=3×3=9

b=3

a×b=21

a×3=21

a=21:3

a=7

a · b = 21

c · c = 81 => c² = 9 => c = √81 = 9

b · b = c => b² = c => b² = 9 => b = √9 = 3

____________

a · b = 21

a · 3 = 21

=> a = 21/3= 7