X=2иy=1,5-уравнение5/8x-by=-4,75
5/16-1,5b=-4.75; -1.5b=-4.75-5/16= (-4.75=-19/4) =-76/16-5/16=-81/16; b=81/16:1.5= (1.5=3/2) =81/16*2/3=27/8=3.375