.把方程x+3=4x配方,得( ) A.(x-2)2=7 B.(x+2)2=21 C.(x-2)2=1 D.(x+2)2=2

问题描述:

.把方程x+3=4x配方,得( ) A.(x-2)2=7 B.(x+2)2=21 C.(x-2)2=1 D.(x+2)2=2


x²+3=4x吗
x²-4x+3=0
x²-4x+4=1
(x-2)²=1
选C