Question

if 2x+3y=13 and xy=6,find 8x^2+27y^3​

Answer 1

Answer:8x^3+27y^3

Step-by-step explanation:

8x^3+27y^3

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

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

(a^2-ab+b^2) where a=x,and b=3y

Therefore

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

(4x^2-6xy+9y)^2

13(4x^2+9y^2-36)

Squaring 2x+3y=13

We get,

4x^2+9y^2=169-72=97

Putting the value in earlier equation we get,8x^3+27y^3=13(47-36)

=13×61

=7•••••answer

I hope it helps. .