<span>1. 24,72 : 1,2+ 0,7 × 5,3 - 0,031 : 0,1=24,3069
1) 24,72:1,2=20,6
2) 0,7*5,3=3,71
3) 0,031*0,1=0,0031
4) 20,6+3,71=24,31
5) 24,31-0,0031=24,3069
2. 90</span>
1-1
2-1,2
3-1,3
6-1,2,3,6
7-1,7
14-1,2,3,4,7,14
21-1,3,7,21
1) VI + V = XI
2) XI - X = I
3) XII - IX = III
4 5/12 - 1 1/2 : (2 1/6 + 8/15) * 1 4/5 = 3 5/12
1) 2 1/6 + 8/15 = 2 5/30 + 16/30 = 2 21/30 = 2 7/10
2) 1 1/2 : 2 7/10 = 3/2 : 27/10 = 3/2 * 10/27 = (1*5)/(1*9) = 5/9
3) 5/9 * 1 4/5 = 5/9 * 9/5 = 45/45 = 1
4) 4 5/12 - 1 = 3 5/12