Question

If x=2y+6,then prove that x^3-8y^3-36xy-216=0​

Answer 1

Step-by-step explanation:

so given

x = 2y+6

⇒ x - 2y = 6      ...... (i)

cubing both sides

⇒ x³ - 8y³ - 6xy(x - 2y) = 216

⇒ x³ - 8y³ - 6xy(6) = 216      {since , x - 2y = 6 from i}

⇒x³ - 8y³ - 36xy - 216 = 0

so the value of x³ - 8y³ - 36xy - 216 = 0  ANSWER