minimize f(x1,x2)=-9x1-10x2+100(-ln(100-x1-x2)-ln(x1)-ln(x2)-ln(50-x1+x2))
on X = {(x1,x2)|x1>0,x2>0,x1+x2<100,x1-x2<50}.Implement Newtons method using 
starting points x(0)=(8,90) and (1,40).show results of iterations till convergence