Answer:
The binomial theorem is a mathematical formula that allows us to expand a binomial expression of the form (a + b)^n, where a and b are any two numbers and n is a positive integer.
We use it because it makes expanding these expressions a whole lot easier! Imagine you need to expand (a + b)^7. Do you think it would be easier to distribute and calculate each product, or use the binomial theorem to find the coefficients quickly?
hope this helps :)