Question

If a³ +b³ = 1344 and a+b = 28, then (a + b)² - 3ab is equal to..?

Answer 1

Answer :-

Given :

a³ +b³ = 1344

a+b =28

To find :

(a+b) ²-3ab=?

Formula used :

(a+b) ³=a³+b³+3ab(a+b)

Solution :

(28)³=1344+3ab(28)

21,952=1344+3ab(28)

21,952-1344=3ab(28)

20,608/28 = 3ab

736 =3ab

Now on putting all the values in the equation we get,

$= > {(a + b)}^{2} - 3ab$

$= > {(28)}^{2} - 736$

$= > 21952 - 736 = 21216$

Therefore the answer is 21,216.