A)-28+20:(-4) ; б) 4,8×6,37+4,8×3,63
-28-5=-33 4,8*(6.37+3.63)=4.8*10=48
-28+20/(-4)= - 33 20 / (-4) = - 5 -28 + ( - 5) = - 33 4,8 × 6,37 + 4,8 × 3,63 = 48 4,8*6,37=30,576 4,8*3,63=17,424 30,576+17,424= 48