a^3+a^3= (-a^2)^3= (-a^3)^2= (-x)^2×(-x)^5×(-x^4)= 已知x-y=5,xy=12,求x^2+y^2的值.

问题描述:

a^3+a^3= (-a^2)^3= (-a^3)^2= (-x)^2×(-x)^5×(-x^4)= 已知x-y=5,xy=12,求x^2+y^2的值.
a^3+a^3=
(-a^2)^3=
(-a^3)^2=
(-x)^2×(-x)^5×(-x^4)=

x^2+y^2=(x-y)^2+2*xy=25+24=49,你前面说的我看不懂啊.