Question

if a+b = 4 and a^3+b^3 = 28. find a^2+b^2​

Answer 1

Answer:

10

Step-by-step explanation:

let a be 3 and b be 1

now on applying it on equation we get

3+1 =4

3^3 + 1^3 = 28

27 + 1 = 28

3^2 + 1^2 = ?

9 + 1 = ?

10 = ?.

Answer 2

Answer:

10

Step-by-step explanation:

using id.

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

4^3 = 28 + 3ab (4)

64 - 28 = 3ab x 4

36/4 = 3ab

9/3 = 3 = ab

now ,using id.

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

4^2 = a^2 + b^2 + 2 (3)

16 - 6 = 10 = a^2 + b^2

hence , a^2 + b^2 = 10