Question

a fracao que representa a dizima periodica 2,9777

Answer 1

2,9777...= 
2,9+7/90= 
29/10+7/90= 
(261+7)/90= 
268/90= 
134/45 
Letra b.

Answer 2

2,9777... = x

29,777... = 10x

29 + 0,777... = 10x

0,777... = 7/9

$29 + \frac{7}{9} = 10x \\ \\ \frac{261}{9} + \frac{7}{9} = 10x \\ \\ \frac{268}{9} = 10x \\ \\ \frac{268}{9} \times \frac{1}{10} = x \\ \\ x = \frac{268}{90} = \frac{134}{45}$