X^4-10x^2+9 = 0 x^5-29x^3+100x=0 (2x^2+3)^2-7(2x^2+3)+10=0 (x^2-16)*(x^3-1)=0 6x^3-x^2+20x+12=0
X^2=a a^2-10x+9=0 D=100-36=64 a(1)=(10+6)/2=8 a(2)=(10-6)/2=2 x^2=2 x=2^1/2 x^2=8 x=8^1/2