Пошаговое объяснение:
1) 3 + 4/6 = 3 + 2/3 = 3 2/3
2)
x/14 = 4/7
7*x = 14*4
7x = 56
x = 56 : 7
x = 8
x/6 = 98/21
21x = 98*6
21x = 588
x = 588 : 21
x = 28
45:5x = 9 : 4
5x*9 = 45*4
45x = 180
x = 180:45
x = 4
4 : 2 2/7 = 5/8 : x
4*x = 5/8 * 2 2/7
4x = 5/8 * 16/7
4x = 10/7
x = 10/7 * 1/4
x = 5/14
2
