Răspuns:
140x11=140x(10+1) =
=1400+140 =
= 1540
250x11 = 250x(10+1)
= 2500+250 =
= 2750
121x11 = 121x(10+1) =
= 1210+121 =
=1331
301x11 = 301x(10+1) =
= 3010+301 =
= 3311
Spor la treaba