(急速 现1小时内)用适当的方法解下列一元二次方程 (1)25x^-144=0 (2)3x(1-x)=2x-2 (3)x

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  • (1)25x^2-144=0

    (5x-12)(5x+12)=0

    x=12/5或x=-12/5

    (2)3x(1-x)=2x-2

    3x(1-x)+2-2x=0

    3x(1-x)+2(1-x)=0

    (3x+2)(1-x)=0

    x=-2/3或x=1

    (3)x^2+3x+2=0

    (x+2)(x+1)=0

    x=-2或x=-1

    (4)√2x^2+3x-2√2=0

    (√2x-1)(x+2√2)=0

    x=√2/2或x=-2√2

    (5)(√2-1)x-2x^2=0

    x[(√2-1)-2x]=0

    x[2x*-(√2-1)]=0

    x=0或x=(√2-1)/2

    (6)(√3+√2)x^2+2√3x+(√3-√2)=0

    [(√3+√2)x+(√3-√2)](x+1)=0

    x=(√3-√2)/(√3+√2)或x=-1

    x=(√3-√2)^2/(√3+√2)(√3+√2)或x=-1

    x=5-2√6或x=-1

    (7)(2m+1)^2+3(2m+1)+2=0

    (2m+1+1)(2m+1+2)=0

    (2m+2)(2m+3)=0

    2(m+1)(2m+3)=0

    (m+1)(2m+3)=0

    m=-1或m=-3/2