3 3/10:(1/4x+5/12)-2 3/5=7/10 Заранее благодарна
3 3/10:(1/4x+5/12)-2 3/5=7/10
1/4x=7/10-3 3/10-5/12+2 3/5
1/4x=-3 4/10-1 1/60
1/4x=-4 25/60
x=-4 25/60:1/4
x=17 10/15