Question

If 3x – 2y =13 and xy = 5, find the value of 27x3 – 8y3

Answer 1

here 
after solving this equation
we will find that x=5 and y=1
then 27x^3-8y^3
=27*125-8*1
=3375-8
=3367

Answer 2

Answer:

3367

Step-by-step explanation:

The two equations are:

3x-2y=13 and xy=15

Now, if 3x-2y=13, then x=$\frac{13+2y}{3}$

Putting the value of x in xy=15, we have

$(\frac{13+2y}{3})y=5$

$2y^{2}+13y-15=0$

$2y^{2}+15y-2y-15=0$

On solving we get y=1, then x=5

Now, $27x^{3}-8y^{3}=27(5^{3})-8(1)=27(125)-8=3375-8=3367$