Помогите !! используя основное свойство дроби,найдите значение х 2) 39/57= 13/8х-5 4) 5х-6/9=70/45

2) 39 / 57 = 13 / (8х-5), 39 / 57 = 3*13 / (8х-5)*3, 39 / 57 = 39 / (8х-5)*3, 57 = (8х-5)*3, 8х-5 = 57 : 3, 8х-5 = 19, 8х = 19 + 5, 8х = 24, х = 3,  4) (5х-6) / 9 = 70 / 45, 5*(5х-6) / 9*5 = 70 / 45, 5*(5х-6) / 45 = 70 / 45, 5*(5х-6) = 70, 5х-6 = 70 : 5, 5х-6 = 14, 5х = 14+6, 5х = 20, х = 4