Question

write the following expression using python syntax (b) 5a3 + 8b -21​

Answer 1

Answer:

solve on notebook -just_sam_07

Answer 2

Answer:

5a^3-13

Explanation:

Factoring:  5a3-13 

Theory : A difference of two perfect cubes,  a3 - b3 can be factored into

              (a-b) • (a2 +ab +b2)

Proof :  (a-b)•(a2+ab+b2) =

            a3+a2b+ab2-ba2-b2a-b3 =

            a3+(a2b-ba2)+(ab2-b2a)-b3 =

            a3+0+0-b3 =

            a3-b3

Check :  5  is not a cube !