am nevoie de alutor dau coroana

a. 78 × (10 + 1) =
78 × 10 + 78 × 1 =
780 + 78 =
858
b. 284 × (10 + 1)
284 × 10 + 284 × 1 =
2840 + 284 =
3124
c. 483 × (10 + 1)
483 × 10 + 483 × 1 =
4830 + 483 =
5413