Пошаговое объяснение:

1) 5×6+5×7= 5×(6+7) = 5 × 13 = 65

2) 14×17 + 7×3 - 7×8 = 7(2×17+3-8) = 7(34+3-8) = 7×29 = 203

3) 1/5 × 31 + 30 : 5 = 1/5 × 31 + 30/5 = 1/5 × 31 + 30 × 1/5 = 1/5 (31 + 30) = 1/5 × 61 = 61/5 = 12,2

[tex]\displaystyle 1)5*6+5*7=5(6+7)=5*13=65\\\\2)14*17+7*3-7*8=238+21-56=203\\\\3)\frac{1}{5}*31+30:5=\frac{31}{5}+6=\frac{61}{5}=12\frac{1}{5}=12,2[/tex]