Question

factorise 8(a+2b)^2 -18(c+3d)^2

Answer 1

8(a+2b)^2 - 18(c+3d)^2

=> 2[ 4(a+2b)^2 - 9(c+3d)^2]

=> 2[ {2(a+2b)}^2 - {3(c+3d)}^2]

=> 2 [ (2a+4b)^2 - (3c+9d)^2]

=> 2 ( 2a+4b + 3c + 9d) (2a+4b-3c - 9d)

Answer 2

Hey friend, Harish here.

Here is your answer
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

$8(a+2b)^{2}-18(c+3d)^{2}$

⇒$2(4(a+2b)^2 -9(c+3d)^2)$

⇒$2((2(a+2b))^2 -(3(c+3d))^2)$  - ( Now, use a²-b² = (a+b)(a-b))

⇒$2(2a+4b+3c+9d) ( 2a+4b-3c-9d)$
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Hope my answer is helpful to u.