Question

the following real number have decimal expansions as given below. in each case decide whether they are rational or not. if they are rational, and of the form P/q,what can you say about the prime factor of q (1)
43.123456789​

Answer 1

Answer:

Yes it is rational

$\frac{43123456789}{1000000000}$ = 43.123456789

the prime factors of q are

$2^{9} (5^{9})$ i.e. the q is multiple of either 2 or 5 or both