x+1/x+10 * (x+10) (x-6) / (x-6) (x-1) multiply
x+1/x+10 (x+10) (x-6) / (x-6) (x-1) = x+1/x+10 (x+10) / (x-1) = (x+10) (x+1) / (x+10) (x-1)= (x+1) / (x-1)