(1)6x＾2-7x+1=0（6x-1）（x-1）=0x1=1/6 x2=1(2)5x＾2-18=9x5x^2-9x-18=0(5x+6)(x-3)=0x1=-6/5 x2=3(3)4x＾2-3x=524x^2-3x-52=0(4x+13)(x-4)=0x1=-13/4 x2=4(4)5x＾2=4-2x.5x^2+2x=4x^2+0.4x=0.8x^2+0.4x+0.04=0.84...