1: \(\left(x+1\right)>=x\left(x-1\right)+4\)
=>\(x+1>=x^2-x+4\)
=>\(x+1-x^2+x-4>=0\)
=>\(-x^2+2x-3>=0\)
=>\(x^2-2x+3< =0\)
=>\(\left(x-1\right)^2+2< =0\)(vô lý)
=>\(x\in\varnothing\)
2: 5(x-1)-x(7-x)<x^2
=>\(5x-5-7x+x^2< x^2\)
=>-2x-5<0
=>-2x<5
=>x>-5/2