(根号下5x-6)-(根号下2x-3)=根号下3x-5

问题描述:

(根号下5x-6)-(根号下2x-3)=根号下3x-5
如题

√(5x-6)-√(2x-3)=√(3x-5)
√(5x-6)=√(2x-3)+√(3x-5)
5x-6=2x-3+3x-5+2√[(2x-3)(3x-5)]
5x-6=5x-8+2√[(2x-3)(3x-5)]
1=√[(2x-3)(3x-5)]
(2x-3)(3x-5)=1
6x^2-19x+14=0
(x-2)(6x-7)=0
x=2,或x=7/6
而2x-3≥0,即x≥3/2
所以x=7/6舍去
则x=2