Question

if ab=5 and a-b=2,find the value of a3-b3

Answer 1

Answer:

38

Step-by-step explanation:

Given : $ab=5$

            $a-b=2$

To Find : $a^3-b^3$

Solution :

Formula :$(a-b)^{3} =a^3-b^3-3ab(a-b)$

Substitute the given values

$(2)^{3} =a^3-b^3-(3*5)(2)$

$8=a^3-b^3-(15)(2)$

$8=a^3-b^3-30$

$8+30=a^3-b^3$

$38=a^3-b^3$

Hence the value of $a^3-b^3$ is 38

Answer 2

Answer:

Answer:

38

Step-by-step explanation:

Given : ab=5

           a-b=2

To Find : a^3-b^3

Solution :

Formula :(a-b)^{3} =a^3-b^3-3ab(a-b)

Substitute the given values

(2)^{3} =a^3-b^3-(3*5)(2)

8=a^3-b^3-(15)(2)

8=a^3-b^3-30

8+30=a^3-b^3

38=a^3-b^3

Hence the value of a^3-b^3 is 38

Step-by-step explanation: