Question

Please tell me i am unable to solve it

Answer 1

hope this helps you .......

Answer 2

25a^2 -4b^2+28bc -49c^2
=25a^2 - (4b^2-28bc+49c^2)
=(a^2-b^2)= (a^2-2ab + b^2)
=(5a)^2 - {(2b^2 - 2*2b*7c + 7c^2)}
=(5a)^2 - ( 2b- 7c)^2
=(a-b) = (a+b) (a-b)
={5a+ (2b- 7c)} {5a^2 - ( 2b - 7c)}
=(5a+2b-7c) (5a-2b+7c) ans.
May you find it helpful.....