a+b =17 এবং ab=60 হলে a-b = কত?
A
7
B
8
C
9
D
10
Correct Answer: 7
আমরা জানি,(a−b)² = (a + b)² −4ab = (17)²−4×60 = 289−240 = 49সুতরাং (a−b)2 = a−b = √49 = 7