Question

Factorise the expressions

a)25 a²-9 b²​

Answer 1

Step-by-step explanation:

25 a² it is written as (5a)²

9 b² is written as (3b)²

so 25 a²-9 b² written as (5a)²-(3b)²

so it is in the form (a)²-(b)²=(a+b) (a-b)

so (5a)²-(3b)²=(5a+3b)(5a-3b)

Answer 2

Answer :

$\large \sf (5a+3b)(5a-3b)$

Solution :

Question :

Factorise the expressions : 25a²- 9b²

Let's solve,

$\sf \bigstar \color{red} 5a^2 \: can \: be \: written \: as \: \underline{(5a)^2 }$

$\sf \bigstar \color{red} 9b^2 \: can \: be \: written \: as \: \underline{(3b)^2 }$

So,

25a²- 9b² can be written as 5a² - 3b².

$\underline{\color{green}{ \: \: \: \: \: \dag \: \: \sf a^2-b^2 = (a+b)(a-b)}}$

$\sf \implies 5a^2-3b^2 = (5a+3b)(5a-3b)$

Therefore,

(5a+3b)(5a-3b)

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