Question

急!求高手帮忙解二元一次方程! 1. 2X的平方-X-3=0 2. (2X-1)的平方-(2X-1)-3=0 急!在线等

Answer 1

1. 2x^2-x-3=0

(x+1)(2x-3)=0

x1=-1 x2=2/3

2. (2x-1)^2-(2x-1)-3=0

4x^2-4x+1-2x+1-3=0

4x^2-6x-1=0

x^2-3/2x-1/4=0

(x-3/4)^2=4/16+9/16

x-3/4=正负根号下13/4

x1=3+根号下13/4 x2=3-根号下13/4