1.
а) 7 ÷ 7/3 + 4 ÷ 4/3 = 7*3/7 + 4*3/4 = 3+3= 6
б) 57/7 - 29/7 ÷ 29/8 = 57/7 - 29*8/29*7= 57/7 - 8/7 = 49/7 = 7
в)(62/5 - 31/5) ÷ 31/4= 31/5 ÷ 31/4 = 31*4/31*5= 4/5
г) 7/3 * 6/7 - 9/4÷23/4 = 2 - 9*4/23*4=2-9/23= 2-0,4= 1,6
2.
а)1,8*0,4 + 6,4 ÷0,16 = 9/5*2/5 + 32/5*5/8= 18/25+4 = 0,72+4 = 4,72
б)4,24 - 17,05:12,5= 4,24 - 341/20:25/2= 4,24 - 341*2/20*25 = 4,24 - 341/250= 4,24 - 1,364=2,876
в)(6,33-3,21):3,75= 3,12 :3,75= 0,832
г)42,6:85,2-64,8:21,6= 0,5 - 3=-2,5