Calculate the value of the expression 1/2 - 2/3x for x = 0.5, x = -6, and x = 4.

Решение:

• При x = 0.5 (или 1/2):

  \[ \frac{1}{2} - \frac{2}{3} \cdot \frac{1}{2} = \frac{1}{2} - \frac{2}{6} = \frac{1}{2} - \frac{1}{3} = \frac{3}{6} - \frac{2}{6} = \frac{1}{6} \]

• При x = -6:

  \[ \frac{1}{2} - \frac{2}{3} \cdot (-6) = \frac{1}{2} + \frac{12}{3} = \frac{1}{2} + 4 = 4.5 \]

• При x = 4:

  \[ \frac{1}{2} - \frac{2}{3} \cdot 4 = \frac{1}{2} - \frac{8}{3} = \frac{3}{6} - \frac{16}{6} = -\frac{13}{6} = -2 \frac{1}{6} \]

Ответ: 1/6; 4.5; -2 1/6.