Question

ab=5, a-b=4
(a3 +b3) = ?​

Answer 1

this is your answer...........

Answer 2

Answer:

$a^3+b^3=126$  

Step-by-step explanation:

Given : $ab=5,a-b=4$

To find : The value of $a^3+b^3$ ?

Solution :

We know the identity,

$(a+b)^2=(a-b)^2+4ab$

Substitute the values in the formula,

$(a+b)^2=(4)^2+4(5)$

$(a+b)^2=16+20$

$(a+b)^2=36$

$(a+b)=6$

Now, we add the equation  $a-b=4$ and $a+b=6$

$a+b+a-b=6+4$

$2a=10$

$a=5$

Substitute back in equation $a-b=4$

$5-b=4$

$b=1$

So, Value of a=5 and b=1

Substitute in $a^3+b^3$

$a^3+b^3=5^3+1^3$

$a^3+b^3=125+1$

$a^3+b^3=126$