16/(x+6)(x-1)=(x+2)(x+3)
16/x^2-x*1+6x-6=x^2+x*3+2x+6
16=(x^2-x+6x-6)x^2+(x^2-x+6x-6)x*3+(x^2-x+6x-6)2x+(x^2-x+6x-6)*6
16=(x^2+5x-6)x^2+(x^2+5x-6)x*3+(x^2+5x-6)*2x+(x^2+5x-6)*6
16=x^4+x^2*5x-x^2*6+x*3x^2+x*3*5x-x*3*6+2xx^2+2x*5x-2x*6+6x^2+6*5x-36
16=x^4+x^3*5+x^3*3+2x^3-6x^2+6x^2+x^2*15+10x^2-x*18-12x+30x-36
16=x^4+5x^3+3x^3+2x^3+25x^2-18x+18
16=x^4+10x^3+25x^2-36
x^4+10x^3+25x^2-36=16
x^4+10x^3+25x^2=52