Question

In the expression (x + y)8, if x = 0.3 and y = 0.7, what is the numerical value of the third term?

Answer 1

why not use the binomial expansion

\[^nC_{r} (x)^{n - r}y^r\]

you will have n = 8 and r = 2

the reason you have r = 2 is that for combinations you start at r = 0

substitute the values then calculate the answer.