Question

Очень срочно 1 задание

Answer 1

$(x - 3)(x - 7) - 2x(3x - 5) = x {}^{2} - 7x - 3x + 21 - 6x {}^{2} + 10x = - 5x {}^{2} + 21$

$2(x + 1) {}^{2} - 4x = 2(x {}^{2} + 2x + 1) - 4x = 2x {}^{2} + 4x + 2 - 4x = 2x {}^{2} + 2 = x {}^{2} + 1$

$4x(x - 2) - (x - 4) {}^{2} = 4x {}^{2} - 8x - (x {}^{2} - 8x + 16) = 4x {}^{2} - 8x - x {}^{2} + 8x - 16 = 3x {}^{2} - 16$