3 3/7 * 1 1/6 - 7/15 * 1 19/21 = 3 1/9
1) 3 3/7 * 1 1/6 = 24/7 * 7/6 = 24/6 = 4
2) 7/15 * 1 19/21 = 7/15 * 40/21 = (1*8)/(3*3) = 8/9
3) 4 - 8/9 = 3 целых 9/9 - 8/9 = 3 1/9
14 • 5 = 70 , 720 : 90 = 8 , 8•2 = 16 , 70 + 16 = 86
<span>73y-y-22y+40=190</span>
<span>50y=190-40</span>
<span>50y=150</span>
<span>y=150/50</span>
<span>y=3</span>