Although I can find lots of examples using the binomial to approximate the hypergeometric for very large values of <span>NN</span>, I couldn't find a full proof of this online.
Exponents signify how many times the base is multiples by itself. In the case of 7x7, 7 is the base and it is being multiplied by twice itself, resulting in an answer of 7^2
So first you want to draw out you triangle and label everything so side a would be x, side b would be 15 and c would be x next the angles need to be label and finally the anwser is 150m