Please help (15 points) !!!!!
removable discontinuity of 1. d(x)=(x^2-12x+20)/(3x) 2. z(x)=(x^2-7x-8)/(x^3+64) 3. f(x)=(2x^3-3x+1)/(x^3-5x+7) 4. y=(x^2+4x-5)/(x^2+8x+15)