For (a+b) =7 and ab = 12, (a-b) =?
A
1
B
2
C
3
D
4
Correct Answer: 1
দেওয়া আছে, a + b = 7, ab = 12, a - b = ? আমরা জানি, (a - b)2 = (a + b)2 - 4ab = (7)2 - 4 × 12 = 49 - 48 = 1 অতএব, a - b = 1