14. a) 0,4 * 3,7= 1,48
b) 3,5 * 1,5 = 5.25
c) 2,25 * 1,6 = 3.6
d) 1,5 * 2,4 = 3,6
15. a) 0,(6) = 6/9 = 2/3
2/3 +4/3 = 6/3 = 2
b) 0,1(3) = (13-1)/90 = 12/90 = 4/30= 2/15
0,9(3)= (93-9)/90 = 84/90 = 42/45 = 16/15
2/15 + 16/15 = 18/15 = 6/5
c) 0,(75) = 75/99 = 25/33
25/33 + 8/33 = 33/33 = 1
d) 0,(63) = 63/99 = 21/33
12/33 + 21/33 = 33/33
