X:(5×6)=3 c×(4×5)=80

Question

X:(5×6)=3 c×(4×5)=80

Answer 1

х : (5 · 6) = 3

х : 30 = 3

х = 3 · 30

х = 90

- - - - - - - - -

с · (4 · 5) = 80

с · 20 = 80

с = 80 : 20

с = 4