binomial expansion

[hollow cairn]

Can someone explain to me how to do 4b?

[peak hare]

its basically asking u to find the coefficient of the 3rd term

the first term x has a power of 0

and coz its the second term in the binomial uno its power increases all the way to p

so u can just increase the power

so assuming u have done a

uno the power

and therefore u know the value to use the combination fucntion

so u would do p choose 3