X平方减6X加9的實數根

X平方减6X加9的實數根


∵x^2-6x+9=(x-3)^2
∴當x=3時原式為0成立



-x的5次方除以x的立方是多少(要過程)


(-x)^5/x^3=-x^5/x^3=-x^(5-3)=-x^2



(x的6次方-y的6次方)除以(x的立方-y的立方)除以(x+y)
如題拆開它~


(x^6-y^6)/(x^3-y^3)/(x+y)
=(x^3+x^3)(x^3-x^3)/(x^3-x^3)/(x+y)
=(x^3+x^3)/(x+y)
=(x+y)(x^2-xy+y^2)/(x+y)
=x^2-xy+y^2