a) 6,75kg + 6,75kg + 6,75kg = 6,75kg x 3 = 20,25kg.

b) 7,14m² + 7,14m² + 7,14m² x 3 = 7,14m² x 1+ 7,14m² x 1+ 7,14m² x 3

= 7,14m² x ( 1 + 1 +3) = 7,14m² x 5 = 35,7m² .

c) 9,26dm³ x 9 + 9,26dm³ = 9,26dm³ x 9 + 9,26dm³ x 1= 9,26dm³ x (9 + 1)

 = 9,26dm³ x 10 = 92,6dm³.