14 фигур:
11 кругов,
1 прямоугольник,
2 квадрата.
1.
<span>1/2+1/3 = 3/6 + 2/6 = 5/6,
3/7+5/8 = 24/56 + 35/56 = 59/56 = 1 3/56,
1/10-1/13 = 13/130 - 10/130 = 3/130,
1/2-1/11 = 11/22 - 2/22 = 9/22,
2.
3/8+4/16 = 6/16 + 4/16 = 10/16 = 5/8,
</span><span>5/24+7/48 = 10/48 + 7/48 = 17/48,
7/9-4/27 = 21/27 - 4/27 = 17/27,
2/15-1/30 = 4/30 - 1/30 = 3/30 = 1/10,
</span>
3.
<span>7/33-3/77 = 49/231 - 9/231 = 40/231,
6/15+1/56 = 336/840 + 15/840 = 351/840 = 117/280,
4/49-5/63 = 36/441 - 35/441 = 1/441</span>
Не 49%, а 35% ..............
3/25 + 11/45 =
= (3*9)/(25*9) + (11*5)/(45*5) =
= 27/225 + 55/225 =
= (27 + 55) / 225 =
= 82/225
45*2=90 км за 2 часа прошел катер 140-90=50 км прошла лодка 50:2=25 км/час скорость лодки