Ответ:
1) 1,2,5,10,13,26,65,130.2)1,3,7,9,21,27,63,189.
1+2+3+4+5+.......................+18=171
171 | 3
57 | 3
19 | 19
1
Ответ: 171 =3*3*19
52/15+7/5=52/15+21/15=73/15=4 13/15.
4/9x = 9/4
x = 5 1/16
<span>3/8÷3/11=а÷2 1/11
11/8= 11/23 *a
a=11/8:11/23 = 23/8= 2 7/8</span>