Question

if x-2y is equal to 6 find the value of x3-8y3-36xy​

Answer 1

Step-by-step explanation:

The given polynomial is x3 - 8y3 - 36xy - 216,

and the condition is x = 2y + 6

So, replacing the value of x in to the polynomial we get,

⇒x3 - 8y3 - 36xy - 216as,x = 2y + 6⇒(2y + 6)3 - 8y3 - 36(2y + 6)y - 216

Now, using the formula of (a + b)3 = a3 + b3 + 3ab(a + b)

and simplifying the equation further,

= (2y)3 + (6)3 + 3(2y)(6)(2y + 6) - 8y3 - 36(2y + 6)y - 216 = 8y3 + 216 + 36(2y + 6)y - 8y3 - 36(2y + 6)y - 216 = 0

Hence, zero is our correct answer