先化简,再求值:2(3x-5)+(x-3)^2,其中x=根号2+1
问题描述：
先化简,再求值:2(3x-5)+(x-3)^2,其中x=根号2+1
答
解；2(3x-5)+(x-3)^2
=6x-10+x^2-6x+9
=x^2-1
将x=根号2+1 代入 方程式得
=(√2+1)^2-1
=2+2√2+1-1
= 2+2√2
答
2(3x-5)+(x-3)^2
=6x-10+x²-6x+9
=x²-1
=(√2+1)²-1
=2+2√2+1-1
=2+2√2
答
2(3x-5)+(x-3)^2
=6x-10+x^2-6x+9
=x^2-1
=(√2+1)^2-1
=2+2√2+1-1
=2+2√2