Question

Resolva as equações 2 elevado a x -15 igual a 16

Answer 1

2^x-15 = 16

2^(x-15) =2^(4)

(x-15)= (4)

x = 4 +15

x = 19

Answer 2

${x}^{2} + x - 15 = 16 \\ {x}^{2} + x- 15 - 16 = 0 \\ {x}^{2} + x - 31 = 0 \\ x = \frac{ - 1 + - \sqrt[2]{ {1}^{2} - 4 \times 1 \times ( - 31) } }{2 \times 1} \\ x = \frac{ - 1 - + \sqrt{1 + 124} }{2} \\ x = \frac{ - 1 + - \sqrt{125} }{2} \\ {x}^{1} = \frac{ - 1 + 5 \sqrt{5} }{2} \\ {x}^{2} = \frac{ - 1 - 5 \sqrt{5} }{2}$