y``=(y`)`=(x*y-x^5)`=(x`)*y+x*y`-5x^4=y+x*y`-5x^4
y``(`1)=1+1*0-5*1^4=-4
y```=(y``)`=(y+x*y`-5x^4)`=y`+x`*y`+x*y``-5*4x^3=y`+y`+x*y``-20x^3
y```(1)=0+0+1*(-4)-20*1^3=-24
y````=(y```)`=(2y`+x*y``-20x^3)`=2y``+x`*y``+x*y```-20*3x^2=2y``+y``+x*y```-60x^2
y````(1)=2*(-4)+(-4)+1*(-24)-60*1^2=-96
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y=1+0*(x-1)+((-4)/2!)*(x-1)^2+((-24)/3!)*(x-1)^3+((-96)/4!)*(x-1)^4+...