Question

If a+b =8 and ab =15 then find the value of a cube +b cube

Answer 1

Answer:

a+b=8    

ab= 15

Step-by-step explanation:

( a+b) ( a+b)=  a square + 2ab + b square

                       a+b =8,    ab= 15

      8+ 2 x 15 =  38

( a+b)( a+b)( a+b)=  (  a square + 2ab + b square)( a+b)= a cube+b cube +3asquareb + 3bsquarea

= a cube +b cube + 3 ( a square b+ b square a)

 38 x 8 = 304