Помогите решить! x²-21x=0 2x²+28x=0 -6x+3x²=0 24x=12x² 81x+9x²x²-21=02x²-128=0-81+9x²4x²=36

x^2 - 21x = 0 x( x - 21 ) = 0 x= 0 x - 21 = 0 x = 21 2x^2 + 28x = 0 2x( x + 14) = 0 2x = 0 x = 0 x + 14 =0 x = - 14 - 6x + 3x^2 = 0 3x^2 - 6x = 0 3x( x - 2) = 0 3x = 0 x = 0 x - 2 = 0 x = 2 - 12x^2 + 24x = 0 x^2 - 2x = 0 x( x - 2) = 0 x = 0 x- 2 = 0 x = 2 x^2 - 21 = 0 x^2 = 21 x = +/- √21 2x^2 - 128 = 0 x^2 - 64 = 0 x^2 = 64 x = +/- 8 9x^2 - 81 = 0 x^2 - 9 = 0 x^2 = 9 x = +/- 3 4x^2 = 36 x^2 = 9 x = +/- 3