Math, asked by iiftva, 3 months ago

a+b=4 a3+b3=28 find a3+b3​

Answers

Answered by glvpragnanreddy
1

28 is answer already given in question

Answered by krishnabhosle2426
0

Answer:

-3

Step-by-step explanation:

We have:

a^3a

3

+ b^3b

3

= 28 and a + b = 4

We have to find, the value of ab = ?

Solution:

a + b = 4

Cubing both sides, we get

∴ (a + b)^3(a+b)

3

= 4^34

3

Using the algebraic identity,

(a + b)^3(a+b)

3

= a^3a

3

+ b^3b

3

+ 3ab(a + b)

⇒ a^3a

3

+ b^3b

3

+ 3ab(a + b) = 64

Put a^3a

3

+ b^3b

3

= 28 and a + b = 4, we get

⇒ 28 + 3ab(4) = 64

⇒ 12ab = 64 - 28 = 36

⇒ ab = \dfrac{36}{12}

12

36

⇒ ab = 3

Thus, the value of ab is "equal to 3".

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