Question

evaluate if a+b =10,ab=21 find a^3+b^3 pls answer ASAP class 9 NCERT​

Answer 1

Answer:

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

=(10)^3-3.21.10

=1000-630

=370

Answer 2

Answer:

Answer is 370

Step-by-step explanation:

Given, a+b=10 , ab=21

we know that,

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

substituting the given values we get,

10^3=a^3+b^3+3*21*10

=> 1000 = a^3 +b^3 + 630

=> a^3 + b^3= 1000-630

=> a^3 + b^3 = 370