Question

factorise 18a*a-50 using appropriate identites

Answer 1

18a² - 50

=> 2(9a² - 25)

=> 2[ (3a)² - (5)²]

By formula, a² - b² = (a+b) (a -b)

Here,

=> 2(3a - 5)(3a + 5)

=> (2)(3a - 5)(3a + 5)


I hope this will help you

(-:

Answer 2

18a×a - 50

$= 18 {a}^{2} - 50 \\ \\ = 2(9 {a}^{2} - 25) \\ \\ = 2( {(3a)}^{2} - {5}^{2} ) \\ \\ = 2(3a + 5)(3a - 5)$

Using following identity


${x}^{2} - {y}^{2} = (x + y)(x - y)$