А) x * 3/5 = 4/15
x = 4/15 : 3/5
x = 4/15 * 5/3
x = 4/9
б) x : 2/7 = 7/12
x = 7/12 * 2/7
x = 1/6
в) 2/3 * x = 4/7
x = 4/7 : 2/3
x = 4/7 * 3/2
x = 6/7
г) 7/9 : x = 7/18
x = 7/9 : 7/18
x = 7/9 * 18/7
x = 2
д) x : 1/2 = 1/2
x = 1/2 * 1/2
x = 1/4
е) 12/25 : x = 3/5
x = 12/25 : 3/5
x = 12/25 * 5/3
x = 4/5