4.71
Пошаговое объяснение:
0.15/0.3 +4.21= 1/3+ 421/100= 471/100= 4.71
0,(15)/0.(3) +4,(21) = 15/99 : 3/9 + 4 21/99 = 5/33 * 3/1 + 4 7/33 = 15/33 + 4 7/33 = 4 22/33 = 4 2/3
4 2/3 = 4,(6)
