Question

x(x+4)-(x-3)(x-5)=
При х= 1/6

Answer 1

$x(x + 4) - (x - 3)( x - 5) = \\ = x {}^{2} + 4x - x {}^{2} + 5x + 3x - 15 = \\ = 4x + 5x + 3x - 15 = \\ = 12x - 15 \\ x = \frac{1}{6} \\ 12 \times \frac{1}{6} - 15 = 2 - 15 = - 13$