Question

(m – n) = 7, mn = 10 , find m2 + n2

Answer 1

Step-by-step explanation:

ANSWER:-

For attempting this question, we need to remember the following identity:-

$\rm{a^2+b^2 = (a+b)^2 - 2ab}$

And also, it has a similar twin too!

$\rm{a^2+b^2 = (a-b)^2 + 2ab}$

Only signs are interchanged, rest is same.

Now what we're gonna do is, substitute the given values to the 2nd identity, as it is satisfied with what is given.

$\rm{a^2+b^2 = (a-b)^2 + 2ab}$

$\rm{m^2+m^2 = (m-n)^2 + 2mn}$

$\rm{m^2+m^2 = (7)^2 + 2(10)}$

$\rm{m^2+m^2 = 49 + 20}$

$\rm{m^2+m^2 = 69 \ is \ the \ answer. }$

So, 69 is the required answer.

Some other identities:-

$\rm{a^2-b^2 = (a+b)(a-b)}$

$\rm{(a+b)^2 = a^2 + b^2 + 2ab}$

$\rm{(a-b)^2 = a^2 + b^2 - 2ab}$

Answer 2

Answer:

69 is the answer

hope this helps