Răspuns:
(a+b)xc=(4209+2103)x6= 6312×6= 37,872
4209×6-2103×6= 25,254-12,618= 12,636
ex 8:
3303×2= 6606 | 2202×3= 6606
4410×2 = 8820 | 2205×4 = 8820
1974×0 = 0 | 2836×0 = 0