Question

If x=2y+6 find the value of x3-8y3 - 36xy-216

Answer 1

Answer:

0

Step-by-step explanation:

$8y {}^{3} + 72y {}^{2} + 216y + 216 - 8y {}^{3} - 72y {}^{2} - 216y - 216$

$72y {}^{2} + 216y + 216 - 72y {}^{2} - 216y - 216$

$0$

Answer 2

Answer:

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