If (a − 2b) = 8 and 2ab = 9, then find the value of (a + 2b).
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 10.
Given that
If (a − 2b) = 8 and 2ab = 9,
As we know,
(a + 2b)2 = (a - 2b)2 + 8ab
Calculation
⇒ (a + 2b)2 = (8)2 + 8 × 9/2
⇒ (a + 2b)2 = 64 + 36 = 100
⇒ a + 2b = 10