In digression, suppose that you wanted to figure out the expansion of an equation such as \(\left(x+y\right)^2\).We may write this as follows \(\left(x+y\right)\left(x+y\right)=x^2+2xy+y^2\).
Now suppose we wanted to expand out \(\left(x+y\right)^3\).
We may write out \(\left(x+y\right)\left(x+y\right)\left(x+y\right)=x^2+xy+y^2\left(x+y\right)=x^3+3x^2y+3xy^2+y^3\).
Notice that if we write the coefficients of these polynomials in the form of a triangle, we will see a pattern