Question

(405)square-(395)squre

Answer 1

Hey dear here is your answer!!!!!!

_________________________

We know that ;

$(a + b)(a - b) = {a}^{2} - {b}^{2} \\ \\ on \: substituting \: the \: value \: \\ \\ (405 + 395)(405 - 395) \\ = 800 \times 10 \\ = 8000$
_________________________
Hope it helps u dear.....✌️✌️✌️⭕⭕⭕

Answer 2

When solving such questions remember the identity,
(a + b)(a - b) = a^2 - b^2

Here,
405^2 - 395^2

We can also write the above terms as,
(405 + 395)(405 - 395)
= 800 * 10
= 8000

The above process was much easier, and free of all complications as compared to normal calculations where we will be calculating the square such great numbers.

So, it is always preferred to solve and simplify any question using identities if possible.