Ребят, срочно, умножение многочленов!Упростите выражение: (x-y) (2x - 3y) - (3x

1) 2x^2 - 3x^2 - 2xy + 3y^2 - (6x^2 + 3xy - 2xy - y^2) = 2x ^2 - 3xy - 2xy + 3y^2 - (6x^2 + xy - y^2) = 2x^2 - 3xy - 2xy + 3y^2 - 6x^2 - xy + y^2 = - 4x^2 - 6xy + 4y^2

2) x^2 + 6x + 4x + 24 - x ^2 = 30

10x + 24 = 30

10x = 6

x = 3/5 = 0.6

3) 2t^2 - 4tu - 2st - tu - 2u^2 + su + st + 2su - s^2 = 2t^2 + 3tu - st - 2u^2 + 3su - s^2

2X^2-3yx-2xy+3y^2-6x^2-3xy+2xy-y= -4x^2-6xy+3y^2-y

x^2+6x+4x+24-x^2=30

10x+24=30

10x=6

x=0,6

2t^2+4tu-2ts-ut-2u^2+us+st+2us-s^2=2t^2+3tu-ts+3us-s^2