If 5x - 14x = 6, x > 0, then find the value of 25x2 - 116x2?
Explanation:
Given, 5x - 14x = 6 ...(1)
Squaring both sides,
5x-14x2 = 36
⇒ 25x2 + 116x2 - 2 × 5x × 14x = 36
⇒ 25x2 + 116x2 + 2 × 5x × 14x - 2 × 2 × 5x × 14x = 36
⇒ 5x+14x2 - 5 = 36
⇒ 5x+14x2 = 41
⇒ 5x + 14x = √41 ...(2)
From (1) × (2)
⇒ (5x)2 - 14x2 = 6√41
Hence, option (a).
Help us build a Free and Comprehensive Preparation portal for various competitive exams by providing us your valuable feedback about Apti4All and how it can be improved.