Question

упростите выражение и найдите его значение :
-4(2,5a-1,5)+5,5a-8 при a = -2/9​

Answer 1

$- 4(2.5a - 1.5) + 5.5a - 8 = - 4 \times 2.5a - 4 \times ( - 1.5) + 5.5a - 8 = - 10a + 6 + 5.5a - 8 = - 4.5a - 2 = - \frac{45}{10} a - 2 = - \frac{9}{2} a - 2 = ...$

при $a = - \frac{2}{9}$

$... = - \frac{9}{2} \times ( - \frac{2}{9} ) - 2 = \frac{9 \times 2}{2 \times 9} - 2 = 1 - 2 = - 1$