<span>(2-17) · (26-16)= -15*10=-150
(-45+15)÷(-10-5)=-30:(-15)=2
-2,5(4у+2)+8(2-13,25у)=-10y-5+16-106y=-116y+11
x=-4</span>
4 2/3 * 6 - 2 23/42 * 3 1/13 + 2 1/8 * 1 29/51 = 23 45/91
1) 4 2/3 * 6 = 14/3 * 6 = 28
2) 2 23/42 * 3 1/13 = 107/42 * 40/13 = 2140/273 = 7 229/273
3) 2 1/8 * 1 29/51 = 17/8 * 80/51 = 10/3 = 3 1/3
4) 28 - 7 229/273 = 27 273/273 - 7 229/273 = 20 44/273
5) 20 44/273 + 3 1/3 = 20 44/273 + 3 91/273 = 23 135/273 = 23 45/91
(5 3/10 - 3 4/5 * 13/38) * 5/84 + 2 1/12 * 4/15 = 50/63
1) 3 4/5 * 13/38 = 19/5 * 13/38 = 13/10 = 1 3/10
2) 5 3/10 - 1 3/10 = 4
3) 4 * 5/84 = 20/84 = 5/21
4) 2 1/12 * 4/15 = 25/12 * 4/15 = 5/9
5) 5/21 + 5/9 = 15/63 + 35/63 = 50/63
Осталось проехать : 100 - 32 = 68% длины маршрута или 127,5 км . Длина маршрута равна : (127,5 / 68) * 100 = 187,5 км
A/b = 6/7 => 7a = 27b => a = 27b/7
(a+3b) / a - ?
7a = 27b | -6a
a = 27b - 6a | +3b
a+3b = 30b - 6a |:a
(a+3b)/a = (30b-6a) / a
(a+3b)/a = (30b - 6*27b/7) : 27b/7
(a+3b)/a = (30b-23_1/7 b) * 7/(27b)
(a+3b)/a = 6_6/7 b * 7/(27b)
(a+3b)/a = 48b/7 * 7/(27b)
(a+3b)/a = 48/27
(a+3b)/a = 16/9