1. 3 7/9 + 5 1/6 = (3 + 5) + (7/9 + 1/6) = 8 + (14/18 + 3/18) = 8 17/18,
2. 8 7/16 + 3 3/10 = (8 + 3) + (7/16 + 3/10) = 11 + (35/80 + 24/80) = 11 79/80,
3. 6 8/12 + 9 7/18 = (6 + 9) + (8/12 + 7/18) = 15 + (24/36 + 14/36) = 15 + 38/36 = 15 + 1 2/36 = 16 1/18,
4. 9 3/6 + 4 7/12 + 3 5/24 = (9 + 4 + 3) + (3/6 + 7/12 + 5/24) = 16 + (12/24 + 14/24 + 5/24) = 16 + 31/24 = 13 + 1 7/24 = 14 7/24.
Стороны у квадрата равны ⇒ корень из 64=8 ( м² ) ⇔ 8*8 = 64 ( м² )
Ответ: 8 метров - сторона.
45y(квадрат)-72y+21.6-13.5y=0
45y(квадрат)-85.5y+21.6=0
получаем квадратное уравнение
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a=45 b=-85.5 c=21.6
D=b(квадрат)-4ac=7310.25-4*45*21.6=7310.25-3888
корень D= 58.5
x=-b+-кореньD /2a
x1=85.5+58.5/90=1.6
x2=85.5-58.5/90=0.3
ОТВЕТ: x = 1.6 и 0,3
86 - 74 = 12 Ответ: на 12 значков Вадима больше, чем у Антона.
1) 7/2 + 13/3 = 21/6 + 26/6 = 47/6 = 7 5/6
2) 1/5 + 36/7 = 7/35 + 180/35 = 187/35 = 5 12/35
3) 62/5 + 64/9 = 558/45 + 320/45 = 878/45 = 19 23/45
4) 4/5 + 19/6 = 24/30 + 95/30 = 119/30 = 3 29/30
5) 43/5 + 11/4 = 172/20 + 55/20 = 227/20 = 11 7/20
6) 15/4 + 1/6 = 90/24 + 6/24 = 96/24 = 4
7) 73/5 + 38/7 = 511/35 + 190/35 = 701/35 = 20 1/35
8) 65/4 + 7/3 = 195/12 + 28/12 = 223/12 = 18 7/12
9) 235/9 + 1/2 = 470/18 + 9/18 = 479/18 = 26 11/18