109 × 9,17 - 5,37 × 72 - 37 × 9,17 + 1,2 × 72 = 9,17 × (109 - 37) - 72 × (5,37 + 1,2) = 9,17 × 72 - 72 × 6,57 = 72 × (9,17 - 6,57) = 72 × 2,6 = 187,2
139 × 15 + 18 × 139 + 15 × 261 + 18 × 261 = 139 × (15 + 18) + 261 × (15 + 18) = 139 × 33 + 261 × 33 = 33 × (139 + 261) = 33 × 400 = 13200
249 × 250 - 250 × 251 + 251 × 252 - 252 × 253 + 254 × 255 = 250(249-251)+252(251-253)+254(253-255)=
=250·(-2)+252·(-2)+254·(-2)=
=-2·(250+252+254)=-2·756= - 1512