Victoria V. answered 10/25/16
Tutor
5.0
(402)
Math Teacher: 20 Yrs Teaching/Tutoring CALC 1, PRECALC, ALG 2, TRIG
Hi Kiranpreet.
I think they are attempting to get you to do a process we call "Completing the Square".
If you take the coefficient of the "x" term and divide it by 2, you get 20/2 = 10
Now square this and get 102= 100.
If you add this squared term to b2+20b you will have
b2+ 20b + 100 and this is
(b+10)2
So want to ADD 100
This makes it the SQUARE of (b+10), a binomial.
Hope that helps. :-)