
Let's solve ~




It's factorized now ~ And if you want to find the zeros then equate the expression with 0.
And you will get ;

We divide 40 by 1/2:-
40 / 1/2 = 40 * 2/1 = 80 answer
I dont know how to delete a answer and i got it wrong apparently so sorry
(a) If

is the mass (in mg) remaining after

years, then


(b)

(c)
Divide 2 by 5.
you get .4
to make a number a percent, you shift the decimal two placed to the right.
so 2/5=.4=40%