Question

If 2x+3y=13 and xy=6, find the value of 8x^3 + 27y^3. Pls answer

Answer 1

Answer:

Question is quite long, pls add more points.

Step-by-step explanation:

Answer 2

793

GIVEN:-

2x+3y = 13 .............(1)

xy = 6......................(2)

TO FIND:-

The value of 8x³+27y³

SOLUTION:-

2x+3y = 13

=> (2x+3y)²= 13²

=> (2x)²+(3y)²+12xy = 169

=> (2x)²+(3y)²+12×6 = 169 from(2)

=> (2x)²+(3y)² = 97 .....(3)

Hence,

8x³+27y³

= (2x)³+(3y)³

= (2x+3y) [ (2x)²+(3y)²- 6xy)

= (13) ( 97 - 6×6) from (2) and (3)

= 13×61

= 793

FORMULA USED:-

(1) A²+B² =A²+B²+2AB

(2) A³+B³ = (A+B)(A²+B²-AB)

hope this helps you