Question

if a cube plus b cube is equal to 9 and a + b is equal to 3 find a and b​

Answer 1

Answer:

Your ans

given:-

a+b=9

Ab=20

to find:-

a3+b3

use formula:-

(a+b)3=a3+b3+3ab(a+b)

(9)3=a3+b3+3×20(9)

729=a3+b3+540

189=a3+b3

Answer 2

Answer

23

Step-by-step explanation:

We will use the formula

a3+b3= (a+b)^3-3ab (a+b)

We will bring 3ab to LHS side and a3+b3 to RHS side

So now inserting the number according to it

3ab×3=9-(3)^3

3ab×3=9-216

3ab×3= - 207

9ab =-207

ab =-207/9

ab =23

Please mark me as brain list