x²+1≥2(3x-4)
x²+1≥6x-8
x²+1-6x+8≥0
x²+9-6x≥0
x²-6x+9≥0
(x-3)²≥0
x²+5≥10(x-2)
x²+5≥10x-20
x²+5-10x+20≥0
x²+25-10x≥0
x²-10x+25≥0
(x-5)²≥0
