It is proved by limit that if the limit of XN is a, then for any natural number k, the limit of XN + k is a

It is proved by limit that if the limit of XN is a, then for any natural number k, the limit of XN + k is a

It is proved that LIM xn = a (n tends to infinity)
Let m = n + K, because K is a natural number and M tends to infinity
So Lim XM = a (M tends to infinity), that is Lim x (n + k) = a
Typing is not easy,

a. If B is a positive integer, a ≠ B, and (90a + 102b) is a perfect square, what is the minimum value of (a + b)?

(90a + 102b) is a complete square number with a factor of 3, and the necessary factor is 3290a + 102b = 32 × (10a + 34 × B3). It is deduced that B is a multiple of 3. It can be seen that (10a + 34 × B3) is also a complete square number, when B = 3, a = 11, (10a + 34 × B3) = 144 = 122, that is, the minimum value of (a + b) is: 11

a. If B is a positive integer, a ≠ B, and (90a + 102b) is a perfect square, what is the minimum value of (a + b)?

(90a + 102b) is a complete square number with a factor of 3. The necessary factor is 3290a + 102b = 32 × (10a + 34 × B3). It is deduced that B is a multiple of 3. Therefore, (10a + 34 × B3) is also a complete square number. When B = 3 and a = 11, (10a + 34 × B3) = 144 = 122, that is, the minimum value of (a + b) is 11 + 3 = 14; answer: the minimum value of (a + b) is 14