12 x-7 при x=0,05

3-1,5x при x=-1/3

(2x-y) : (x-3y) при x-1, y=1/3

А) 12 х-7 = 12*0,05-7 = 0,6-7 = - 6,4

б) 3-1,5 х = 3-1,5 * (-1/3) = 3-3/2 * (-1/3) = 3+1/2 = 3 1/2 = 3,5

в) (2 х-у) : (х-3 у) = (2 * (-1) - 1/3) : (-1-3*1/3) =

-2 1/3: (-2) = - 7/3 * (-1/2) = 7/6 = 1 1/6