✔ 最佳答案
(a + √b)² = 49 + 12√b
a² + 2a√b + (√b)² = 49 + 12√b
a² + 2a√b + b = 49 + 12√b
(a² + b) + 2a√b = 49 + 12√b
Compare the rational parts and irrational parts on the both sides :
a² + b = 49 …… [1]
2a√b = 12√b …… [2]
From [2] :
2a = 12
a = 6
Substitute a = 6 into [1] :
6² + b = 49
36 + b = 49
b = 13
Hence a = 6, b = 13