问题
填空题
已知a+b=5,ab=-14,则a3+a2b+ab2+b3=______.
答案
∵a+b=5,ab=-14,
∴a3+a2b+ab2+b3
=(a3+a2b)+(ab2+b3)
=a2(a+b)+b2(a+b)
=(a+b)(a2+b2)
=(a+b)[(a+b)2-2ab]
=5×(25+28)
=265.
故答案为265.
已知a+b=5,ab=-14,则a3+a2b+ab2+b3=______.
∵a+b=5,ab=-14,
∴a3+a2b+ab2+b3
=(a3+a2b)+(ab2+b3)
=a2(a+b)+b2(a+b)
=(a+b)(a2+b2)
=(a+b)[(a+b)2-2ab]
=5×(25+28)
=265.
故答案为265.