Răspuns :
[tex](c \div 9 \div 3) \times 4 = 20 \\ \\ (c \div 9 \div 3) = 20 \div 4 \\ \\ (c \div 9 \div 3) = 5 \\ \\ c \div 9 = 5 \times 3 \\ \\ c \div 9 = 15 \\ \\ c = 15 \times 9 \\ \\ c = 135[/tex]
( c : 9 : 3 ) x 4 = 20
c : 9 : 3 = 20 : 4
c : 9 : 3 = 5
c : 9 = 5 x 3
c : 9 = 15
c = 15 x 9
c = 135
Verific: (135 : 9 : 3 ) x 4 = ( 15 : 3 ) x 4 = 5 x 4 = 20
c : 9 : 3 = 20 : 4
c : 9 : 3 = 5
c : 9 = 5 x 3
c : 9 = 15
c = 15 x 9
c = 135
Verific: (135 : 9 : 3 ) x 4 = ( 15 : 3 ) x 4 = 5 x 4 = 20