Answer:
7a^6b
Step-by-step explanation:
Using the pascal triangle to do this binomial expansion, we find out that the coefficient is 7. The a variables start at the power to which you are expanding and reduce by 1 for every consecutive term. The b variables start at the power of 0 and increase by 1 for every consecutive term. Using this information, we find out that the second term in the binomial expansion (a+b)^7 is 7a^6b
Note that the power of b in the second term is b^1 which is the same as b
