b) 2,6. (3,42 – x) = –13,52.

b) 2,6. (3,42 – x) = –13,52

3,42 – x = –13,52 : 2,6

3,42 – x = – 5,2

x = 3,42 – (– 5,2 )

x = 3,42 + 5,2

x = 8,62

Vậy x = 8,62.