已知a+b+c=10,a^2+b^2+c^2=38,a^3+b^3+c^3=160,求abc值
问题描述:
已知a+b+c=10,a^2+b^2+c^2=38,a^3+b^3+c^3=160,求abc值
答
( a + b + c )^3= aaa + bbb + ccc + 6abc + 3aab + 3aac + 3abb + 3bbc + 3acc + 3bcc= 6abc + 3aab + 3aac + 3aaa + 3abb + 3bbc + 3bbb + 3acc + 3bcc + 3ccc - 2 ( aaa + bbb + ccc )= 6abc - 2 * 160 + 3aa ( a...