Question

先化简,再求值:2(a+根号3)(a-根号3)-a(a-6)+6,其中a=根号2-1

要过程

Answer 1

2(a+根号3)(a-根号3)-a(a-6)+6
=2(a²-3)-a²+6a+6
=a²+6a
=(√2-1)²+6(√2-1)
=4√2-3

Answer 2

2(a+根号3)(a-根号3)-a(a-6)+6
=2（a^2-3）-a^2+6a+6
=a^2+6a
=a(a+6)
=(√2-1)(√2+5)
=4v2-3