Question

x ^ 2 - 9y ^ 2


factories​

Answer 1

Question :

Factorise

$\tt {x}^{2} - 9{y}^{2}$

Identity :

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

Solution :

$\tt {x}^{2} - 9{y}^{2}$

$\tt \implies {x}^{2} - {(3y)}^{2}$

$\tt \implies$ (x-3y)(x+3y)

$\tt {x}^{2} - 9{y}^{2}$ = (x-3y)(x+3y)

Some other identities :

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

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

● $\tt {(a+b+c)}^{2} = {a}^{2} + {b}^{2} + {c}^{2} + 2(ab+bc+ac)$

● $\tt {(a+b)}^{3} = {a}^{3} + {b}^{3} + 3{a}^{2}b + 3a{b}^{2}$

● $\tt {(a-b)}^{3} = {a}^{3} - {b}^{3} + 3a{b}^{2} - 3{a}^{2}b$

Answer 2

Answer:

happy friendship day vrutu