Question

3x²-5x=0 x^2-5x-24 =0
7x^2-22x+3=0
7x^2-6x+2=0
4x^2+12x+9=0

Answer 1

1) 3x^2 - 5x = 0
x( 3x - 5 ) = 0
x = 0   3x=5
            x = 5/3
корни 0 и 5/3
2) x^2 - 5x - 24 = 0
x1 + x2 = 5
x1 * x2 = -24 (теорема Виета )
x1 = 8     x2 = -3
3) 7x^2 - 22x + 3 = 0
D = 484-84 = 400 = 20^2
x1 = 3
x2 = 1/7
4) 7x^2 - 6x + 2 = 0
D = 36-56 < 0
D<0 корней нету
5) 4x^2 + 12x + 9 = 0
D = 144-144 = 0
D = 0 только один корень
x = -12/8 = -3/2 = -1.5