Question

17) Calcule o valor de x
128^x+2 = 256^2x-5
A) 4
B) 5
C) 6
D) 7
E) 8​

Answer 1

${128}^{x + 2} = {256}^{2x - 5} \\ ( {2}^{7} )^{x + 2 } = ( {2}^{8} )^{2x - 5} \\ 7x + 14 = 16x - 40 \\ 14 + 40 = 16x - 7x \\ 54 = 9x \\ x = \frac{54}{9} = > 6$