a + b = 9m এবং ‍ab = 18m2 হলে a

a + b = 9m এবং ‍ab = 18m² হলে a - b =?

A 3m

B -3m

C 6m

D 8m

E a ও b উভয়ই

Correct Answer: Option E

আমরা জানি, (a – b)² = (a + b)² - 4ab
⇒ (a - b)² = (9m)² – ( 4 ×18) m
⇒ (a - b)² = 81m²- 72m²
∴ a - b = ± √((81m² - 72m²)
= ± √(9m²)
= ± 3m