(2x-1)" -7 = 3(x+1)
4x" -4x +1 -7 = 3x +3
4x" -7x -9 =0
配方计算,就是
x" -(7/4)x =(9/4)
x" - 2(7/8)x +(7/8)" = 144/64 +49/64
(x - 7/8)" = 193/64
x - 7/8 = 正负(根号193) /8
x1 = 7/8 +(根号193)/8 = (7+ 根号193)/8
x2 = 7/8 -(根号193)/8 = (7- 根号193)/8
如果用公式法,就是
x= { -(-7) 正负根号[ (-7)" -4(-9)4] } / 2X4
x= { 7 正负根号[ 49+144 ] } / 8
x= ( 7 正负根号193 )/ 8
x1 = (7+ 根号193)/ 8
x2 = (7- 根号193)/ 8
这样有个根号193,好像就不能用因式分解法来求解了.