X的平方+2X+2=8X+4 X的平方-2X-4=0

问题描述:

X的平方+2X+2=8X+4 X的平方-2X-4=0

x²+2x+2=8x+4
x²+2x-8x=4-2
x²-6x=2
x²-6x+3²=2+3²
(x-3)²=11
x-3=±√11
x=3±√11
x1=3+√11
x2=3-√11

x²-2x-4=0
x²-2x+1=5
(x-1)²=5
x-1=±√5
x=1±√5
x1=1+√5
x2=1-√5

x^2+2x+2=8x+4
x^2-6x=2
x^2-6x+9=11
(x-3)^2=11
x=3+√11或x=3-√11
x^2-2x-4=0
x^2-2x=4
x^2-2x+1=5
(x-1)^2=5
x=1+√5或x=1-√5