若a2+2ab=-10,b2+2ab=16,则多项式a2+4ab+b2与a2-b2的值分别为( ) A.6,26 B.-6,26 C.6,-26 D.-6,-26
问题描述:
若a2+2ab=-10,b2+2ab=16,则多项式a2+4ab+b2与a2-b2的值分别为( )
A. 6,26
B. -6,26
C. 6,-26
D. -6,-26
答
∵a2+2ab=-10,b2+2ab=16,
∴a2+4ab+b2
=(a2+2ab)+(b2+2ab),
=-10+16,
=6;
∴a2-b2
=(a2+2ab)-(b2+2ab),
=-10-16,
=-26.
故选C.