(1)x^2-2根号3乘以x=0 (2)3x^2-6x=3 (3)3x(x-2x)=3 (4)3x^2-6x-3=0 (

1个回答

  • 1、0 或 2根号3 (提取x)

    2、1加减根号2

    Possible intermediate steps:

    3 x^2-6 x = 3

    Divide both sides by 3:

    x^2-2 x = 1

    Add 1 to both sides:

    x^2-2 x+1 = 2

    Factor the left hand side:

    (x-1)^2 = 2

    Take the square root of both sides:

    abs(x-1) = sqrt(2)

    Eliminate the absolute value:

    x-1 = -sqrt(2) or x-1 = sqrt(2)

    Add 1 to both sides:

    x = 1-sqrt(2) or x-1 = sqrt(2)

    Add 1 to both sides:

    x = 1-sqrt(2) or x = 1+sqrt(2)

    注:abs 绝对值 ,sqrt 平方根

    3、无实数根、如果你学过复数看下面解题

    Possible intermediate steps:

    -3 x^2 = 3

    Divide both sides by -3:

    x^2 = -1

    Take the square root of both sides:

    x = -i or x = i

    4、同(2)

    5、正负二分之十一

    Possible intermediate steps:

    4 x^2-121 = 0

    Add 121 to both sides:

    4 x^2 = 121

    Divide both sides by 4:

    x^2 = 121/4

    Take the square root of both sides:

    x = -11/2 or x = 11/2

    毕.