1 6/15 x 2 8/9 – 2,7 x 1 1/8

1 6/15 × 2 8/9 – 2,7 × 1 1/8 =
21/15 × 26/9 – 27/10 × 9/8 =
546/135 – 243/80 =
43680/10800 – 32805/10800 =
10875/10800 = 1 75/10800

3,08 – 3,71
= 3,1 – 3,7
= -0,6