Question

if a+b=10 and ab=15 find the value of a^3 + b^3 ....
class 9 chapter polynomials.​

Answer 1

Answer:

550

Step-by-step explanation:

a+b=10

ab=15

a^3+b^3={(a+b)^3} -3ab(a+b)

={(10)^3}-3(15)(10)

=1000-450

=550

Answer 2

Answer:

solution:-

Given,

a+b=10 and ab=15

Squaring both sides,we get,

  (a+b)2=72 

=a2+b2+2ab=49                 [since(a+b)2=a2+b2+2ab]

=a2+b2+2(15)=49

=a2+b2=49−30

=a2+b2=19

Now,

  (a3+b3)

=(a+b)(a2+b2−ab)

=7(19−15)

=7(4)

=550