(1)已知a=3,b=1,求a 2 +2ab+b 2 和(a+b) 2 的值;(2)请你再取一组a、b的值,计算代数式a 2 +2ab+

2025-02-26 18:51:44
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回答1:

(1)当a=3,b=1时,
a 2 +2ab+b 2 =3 2 +2×3×1+1 2 =16,
(a+b) 2 =(3+1) 2 =16,
(2)如取a=1,b=-3,
a 2 +2ab+b 2 =1 2 +2×1×(-3)+(-3) 2 =4,
(a+b) 2 =(1-3) 2 =4,
结论:(a+b) 2 =a 2 +2ab+b 2