1、解方程(1)x²-x-3=0 (2)(x+3)²=2(x+3)2、计算√18-2/√2-√8/2+(√5-1)º
问题描述:
1、解方程
(1)x²-x-3=0 (2)(x+3)²=2(x+3)
2、计算
√18-2/√2-√8/2+(√5-1)º
答
1、(1±√13)/2
2、-1,-3
3、√2+1
答
(1)x²-x-3=0
x=(1+根号13)/2,x=(1-根号13)/2
(2)(x+3)²=2(x+3)
(x+3)(x+3-2)=0
x=-3,x=-1
√18-2/√2-√8/2+(√5-1)º=3√2-√2-√2+1=√2+1
答
1、解方程(1)x²-x-3=0 x²-x+1/4=13/4(x-1/2)²=13/4x=1/2+√13/2 x=1/2-√13/2(2)(x+3)²=2(x+3)(x+3)²-2(x+3)=0(x+3)(x+3-2)=0x=-3 x=-12、计算√18-2/√2-√8/2+(√5-1)º=3√...
答
x²-x-3=0
x^2-x=3
x^2-x+1/4=13/4
(x-1/2)^2=13/4
x-1/2=±(√13)/2
x1=(√13+1)/2
x2=(-√13+1)/2
(x+3)²=2(x+3)
(x+3)²-2(x+3)=0
(x+3)(x+3-2)=0
(x+3)(x+1)=0
x1=-3 x2=-1
√18-2/√2-√8/2+(√5-1)º
=3√2-√2-√2+1
=√2+1