1/4//3/4Х-1/2+2/5=1/2

1/4:3/4x-1/2+2/5=1/2 1/4:3/4x=1/2+1/2-2/5 1/4:3/4x=1/2+1/2-2/5 1/4:3/4x=1-2/5 1/4:3/4x=5/5-2/5 1/4:3/4x=3/5 3/4x=1/4:3/5 3/4x=1*5/4*3=5/12 x=5/12:3/4 x=5*4/12*3 x=5*1/3*3=5/9 Ответ: х=5/9