Question

2 la a 9 plus 2 la 10 plus 2 la 11 = n • 2 la 9

Answer 1

${2}^{9} + {2}^{10} + {2}^{11} = n \times {2}^{9}$

$(1 + 2 + {2}^{2} ) \times {2}^{9} = n \times {2}^{9} = (1 + 2 + {2}^{2} ) \times {2}^{9} = {2}^{9} n$

$(1 + 2 + 4) \times {2}^{9} = {2}^{9} n = (1 + 2 + 4) \times 512 = {2}^{9} n = (1 + 2 + 4) \times 512 = 512n$

$7 \times 512 = 512n$

$3584 = 512n$

$512n = 3584$

$n = 7$

Answer 2

Răspuns:

Explicație pas cu pas:

2⁹ + 2¹⁰ + 2¹¹ = n x 2⁹

2⁹ x 1 + 2⁹ x 2 + 2⁹ x 2²= n x 2⁹

-> il dau factor comun pe 2⁹

2⁹ x ( 1 + 2 + 2² ) = n x 2⁹   l : 2⁹

=>   n = 1 + 2 + 4

      n = 7