Question

Me explican estos ejercicios :c?


*no entiendo, help*

Answer 1

Explicación paso a paso:

1)

$2 \times {n}^{2} + 1 \times n + 3 = 81 \\ 2 {n}^{2} + n - 78 = 0 \\ (2n + 13)(n - 6) = 0 \\ n = 6$

2)

$1 \times {4}^{3} + 3 \times {4}^{2} + x \times 4 + 0 = 120 \\ 64 + 48 + 4x = 120 \\ 112 + 4x = 120 \\ 4x = 8 \\ x = 2$

3)

Se observa:

b diferente de 0

a < 5

b < 5

Descomponiendo:

$3 \times {5}^{2} + a \times 5 + b = b \times {6}^{2} + a \times 6 + 1 \\ 75 + 5a + b = 36b + 6a + 1 \\ 35b + a = 74 \\ b = 2 \\ a = 4 \\ a + b = 4 + 2 = 6$