2x^2-7x+3=02(x^2-7/2x+49/16-49/16)+3=02(x-7/4)^2=25/8(x-7/4)^2=25/16x1=1/2;x2=3a=1;b=-2√2;c=-3Δ=b^2-4ac=20>0x1,2=√2±√5
