Problem on Factorization

Topic : Factorization

Problem : Factorise -2w^4 +1250

Solution :
-2w^4 +1250
taking -2 as common
-2(w^4 -625)
-2[(w^2)^2 - (25)^2]
Applying the formula
a^2-b^2 = (a+b)(a-b)
we get -2[(w^2+25)(w^2-25)]
-2[(w^2+25)(w^2-5^2)]
Again applying the formula
for (w^2-5^2)
we get
-2[(w^2+25)(w+5)(w-5)]