Let a + b = 2c, then which of the following expressions is true?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. .
Given that, a + b = 2c
⇒ a - c = c - b
Squaring both sides of the equation,
⇒ (a - c)2 = (c - b)2
⇒ a2 - 2ac + c2 = c2 - 2bc + b2
⇒ a2 - 2ac = b2 - 2bc
⇒ a2 + 2bc = b2 + 2ac
Hence the required answer is a2 + 2bc = b2 + 2ac.