Question

if 3x+2y=20 and
$xy = \frac{14}{9}$
then
$27 {x}^{3} + 8 {y}^{3} =$

Answer 1

Hey!!

Here is your answer >>>

3x + 2y = 20

Xy = 14/9

27x^3 + 8y^3 =?

Let us cube the first equation on both sides!.

(3x + 2y)^3 = (20)^3

27x^3 + 8y^3 +{ 3(3x)(2y)}(3x + 2y)!.

Formula =

(a + b) ^3 = a^3 + b^3 + 3ab(a + b)

27x^3 + 8y^3 + 18xy(3x + 2y)

27x^3 + 8y^3 + 18(14/9)(20)

27x^3 + 8y^3 + 28(20)

27x^3 + 8y^3 + 560 = 800

27x^3 + 8y^3 = 800 - 560

27x^3 + 8y^3 = 240!.

HOPE MY ANSWER HELPS! ✌️