a)f(x+d)-f(x)=3x+3d+5-3x-5=3d
б) f(x+d)-f(x)=-(x+d)^2+x^2=-x^2-d^2-2xd+x^2=-(2xd+d^2)
в) f(x+d)-f(x)=4-2x-2d-4+2x=-2d
г) f(x+d)-f(x)=2x^2+2d^2+4xd-2x^2=2(d^2+2xd)
a)f(x+d)-f(x)=3x+3d+5-3x-5=3d
б) f(x+d)-f(x)=-(x+d)^2+x^2=-x^2-d^2-2xd+x^2=-(2xd+d^2)
в) f(x+d)-f(x)=4-2x-2d-4+2x=-2d
г) f(x+d)-f(x)=2x^2+2d^2+4xd-2x^2=2(d^2+2xd)