若a+b=3则2a²+4ab+2b²-6的值为

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若a+b=3则2a²+4ab+2b²-6的值为
若a+b=3则2a²+4ab+2b²-6的值为

若a+b=3则2a²+4ab+2b²-6的值为
2a²+4ab+2b²-6
=2(a²+2ab+b²)-6
=2(a+b)²-6
因为a+b=3
所以
=2X3²-6
=18-6
=12

2a²+4ab+2b²-6
=2(a+b)^2-6
=2*9-6
=12

2a²+4ab+2b²-6
=2(a²+2ab+b²)-6
=2(a+b)²-6
=2*9-6
=12

12