factor completly b^2-21b-100 answer should look like this(b )(b ) what are the missing numbers can someone p?

b^2 - 21b - 100
= b^2 + 4b - 25b - 100
= (b^2 + 4b) - (25b + 100)
= b(b + 4) - 25(b + 4)
= (b + 4)(b - 25)

(b+4)(b-25)

(b-25)(b+4)

b^2-21b-100

This is the expression and the factorisation is required
So,
b^2 - 21b - 100
= b^2 - 25b + 4b - 100
= b * (b - 25) + 4 * (b - 25)
= (b + 4) * (b - 25)........................(Ans)
Hope this will help u