Math, asked by lussifer7034, 10 months ago

Using the identity ( a-b)² =a² + 2ab + b² . Evaluate
1. 699²
2.393²

Answers

Answered by vishnupanicker

Answer:

( a-b)² =a² - 2ab + b²

699²

(700-1)²= (700)² -2(700)(1) +(1)

490000-1400+1

488601 Ans

( a-b)² =a² + 2ab + b²

393²

(400-7)² =(400)²-2(400)(7) +(7)²

160000-5600 +49

154,449ans

Answered by SparklingYashi

$\huge\bold{\underline{\underline{{Solution:}}}}$

✒As we have to use this formula :

: $\longrightarrow$ $\bold{\boxed{\pink{{( a - b )^{2} = a^{2} - 2ab + b^{2}}}}}$

$\rule{400}1$

➸We can write 699² as ( 700 - 1 )².

$\displaystyle{\sf{( 700 - 1 )^{2} = (700)^{2} - 2 (700)(1) + (1)^{2}}}$

: $\implies$ $\displaystyle{\sf{= 490000 - 1400 + 1}}$

: $\implies$ $\displaystyle{\sf{\boxed{\red{= 488601.}}}}$

$\rule{400}1$

➸We can write 393² as ( 400 - 7 )² .

$\displaystyle{\sf{( 400 - 7 )^{2} = (400)^{2} - 2 (400)(7) + (7)^{2}}}$

: $\implies$ $\displaystyle{\sf{= 160000 - 5600 + 49}}$

: $\implies$ $\displaystyle{\sf{\boxed{\red{154449.}}}}$

${\underline{\rule{400}4}}$

➤ $\large\bold{\underline{{Additionally:}}}$

An algebraic identity is an equality that holds for any values of its variables.

There are four main identities of algebra:

${\underline{\rule{400}4}}$

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