$$(2x-3)(x + 4) = 2x^2 + 8x - 3x - 12 = 2x^2 + 5x - 12$$
Ответ: $$2x^2 + 5x - 12$$
$$(5 - x)(x+3) = 5x + 15 - x^2 - 3x = -x^2 + 2x + 15$$
Ответ: $$-x^2 + 2x + 15$$
$$(3x-1)(x-3) = 3x^2 - 9x - x + 3 = 3x^2 - 10x + 3$$
Ответ: $$3x^2 - 10x + 3$$
$$(5x-2)(2x + 3) = 10x^2 + 15x - 4x - 6 = 10x^2 + 11x - 6$$
Ответ: $$10x^2 + 11x - 6$$
$$3(x-1)(2x-3) = 3(2x^2 - 3x - 2x + 3) = 3(2x^2 - 5x + 3) = 6x^2 - 15x + 9$$
Ответ: $$6x^2 - 15x + 9$$
$$(2x-3)(3x+2)-(3x-2)(2x+3) = (6x^2 + 4x - 9x - 6) - (6x^2 + 9x - 4x - 6) = 6x^2 - 5x - 6 - 6x^2 - 5x + 6 = -10x$$
Ответ: $$-10x$$
$$3(x-3)(x+2)-(3x-1)(x+4) = 3(x^2 + 2x - 3x - 6) - (3x^2 + 12x - x - 4) = 3(x^2 - x - 6) - (3x^2 + 11x - 4) = 3x^2 - 3x - 18 - 3x^2 - 11x + 4 = -14x - 14$$
Ответ: $$-14x - 14$$