Question

$3 \times - 1^{x + 2} + 4 \times { - 1}^{2x + 1} - 5$
Va rog!! Urgent!!​

Answer 1

$3 \times {(-1)}^{x + 2} + 4 \times { (- 1)}^{2x + 1} - 5 = \\ \\ = 3 \times {(-1)}^{x} \times {(-1)}^{2} + 4 \times {(-1)}^{2x}\times {(-1)}^{1}-5=$

$=3 \times ( - 1) {}^{x} \times 1 + 4 \times 1 {}^{2x} \times ( - 1) -5= \\ \\ = 3 \times (- 1 {}^{x} ) + 4 \times 1 \times (-1) -5 \\ \\ = 3 \times ( - 1) {}^{x} - 4 -5=$

$= 3 \times ( - 1) {}^{x} - 9$

• dacă x număr PAR

$= 3 \times 1 - 9 = 3 - 9 = - 6$

• dacă x număr IMPAR

$= 3 \times ( - 1) - 9 = - 3 - 9= - 12$