x = [1.6, 1.2]'
A = [2*x(1),2*x(2);2*x(1),-2*x(2)]
b = [x(1)^2+x(2)^2-4;x(1)^2-x(2)^2+1]
x1 = A \ b
x = x - x1
A = [2*x(1),2*x(2);2*x(1),-2*x(2)]
b = [x(1)^2+x(2)^2-4;x(1)^2-x(2)^2+1]
x1 = A \ b
x = x - x1
A = [2*x(1),2*x(2);2*x(1),-2*x(2)]
b = [x(1)^2+x(2)^2-4;x(1)^2-x(2)^2+1]
x1 = A \ b
x = x - x1