What number do you get when you decrease the ones digit of 2019 by 2?
1 answer:
You might be interested in
Option C:
The coefficient of is 40.
Solution:
Given expression:
Using binomial theorem:
Here
Substitute in the binomial formula, we get
Now to expand the summation, substitute i = 0, 1, 2, 3, 4 and 5.
Let us solve the term one by one.
Substitute these into the above expansion.
The coefficient of is 40.
Option C is the correct answer.