Question

3.Factorise by using suitable identities

b)49x2-25y2​

Answer 1

Answer :

• 49x² - 25y² = (7x + 5y) (7x - 5y)

Given :

• 49x² - 25y²

To find :

• Factorise

Solution :

》49x² - 25y²

》7²x² - 5²y²

》(7x)² - (5y)²

we know that,

• a² - b² = (a + b) (a - b)

》(7x + 5y) (7x - 5y)

Hence, 49x² - 25y² = (7x + 5y) (7x - 5y)

More Explanation :

• a² - b² = (a + b) (a - b)
• (a + b)² = a² + 2ab + b²
• (a - b)² = a² - 2ab + b²
• a³ + b³ = (a + b) (a² - ab + b²)
• a³ - b³ = (a - b) (a² + ab + b²)

Answer 2

✬Correct Question :-✬

$\rm{factorise \: \: {49x}^{2} } - {25y}^{2} \: using \: suitable \: identities✬$

✬Answer✬

$\to \rm \: {49x}^{2} - {25y}^{2}$

$\to \rm {7}^{2} {x}^{2} - {5}^{2} {y}^{2}$

$\to \rm {(7x)}^{2} - {(5y)}^{2}$

$\rm {we \: know \: that\: {a}^{2} - {b}^{2} = ( a+b )( a- b)}$

$\therefore \rm {49x}^{2} - {25y}^{2} \\ \rm= (7 x+ 5y)(7x - 5y)$

$\rm{ \color{cyan}{ ❤| |ur \: shona| | ❤}}$