2x^2-3x-2.5=04x^2-6x-5=0a=4 b=-6 c=-5△=36+80=116x=(6+-2根号29)/轮卜8∴伍或x1=(3-根号29)/4 x2=(3+根号29)/腔桐伍4
(2x*2)+2=3x+4.54x+2=3x+4.54x-3x=4.5-2x=2.5
解:4x=3x+2.5 x=2.5d
(2x*2) 2=3x 4.5 4x-3x=4.5-2 x=2.5