Question

factorise 25p^2 -4q^2 +28qr - 49r^2

Answer 1

25p^2-(4q^2+49r^2-28qr)
25p^2-(2q-7r)^2
(5p)^2-(2q-7r)^2
=>(5p+2q-7r)(5p-2q+7r)

hope you understand and it helps you...

Answer 2

Answer:

25p^2 - 4q^2 + 28qr - 49r^2

25p^2 - (4q^2 - 28qr + 49r^2)

25p^2 - { (2q)^2 - 2(2q)(7r) + (7r)^2 }

(5p)^2 - (2q - 7r )^2

{ 5p - (2q - 7r)} { 5p + (2q - 7r) }

(5p - 2q + 7r) ( 5p + 2q - 7r)