if 8 + 2px2 - 36x - 27x3 = (2 -3x)3, then what is the value of p?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e 27.
8 + 2px2 - 36x - 27x3 = (2 - 3x)3
(a - b)3 = a3 - b3 - 3a2b + 3ab2
⇒ 8 + 2px2 - 36x - 27x3 = 8 - 27x3 - 3 × 4 × 3x + 3 × 2 × 9x2
⇒ 8 - 27x3 + 2px2 - 36x = 8 - 27x3 + 54x2 - 36x
Comparing both sides :
2p = 54
p = 27