Question

Simplify the given expression(5+√7)(5-√7) with slove​

Answer 1

Step-by-step explanation:

(5+√7)(5-√7) (a+b)(a-b)= a²- b²

= 5² - (√7)²

=25-7

=18

Answer 2

Given:-

The given expression (5+√7)(5-√7)

To simplify :-

Formulae to know :-

( a + b ) ( a - b ) = a² - b²

lets simplify

As we know above formula by using the above formulae we can solve

= 5 + $\sf\sqrt{7}$ × 5 - $\sf\sqrt{7}$

Applying above formulae

(a + b ) ( a - b ) = a² - b²

= (5)² - $\sf\sqrt{(7)^2}$

= 25 - 7

= 18

So,

5 + $\sf\sqrt{7}$ × 5 - $\sf\sqrt{7}$ = 18

Know more :-

(a+ b)² = a² + b² + 2ab

( a - b )² = a² + b² - 2ab

( a + b )² + ( a - b)² = 2a² + 2b²

( a + b )² - ( a - b)² = 4ab

( a + b + c )² = a² + b² + c² + 2ab + 2bc + 2ca

a² + b² = ( a + b)² - 2ab

(a + b )³ = a³ + b³ + 3ab ( a + b)

( a - b)³ = a³ - b³ - 3ab ( a - b)

If a + b + c = 0 then a³ + b³ + c³ = 3abc