Question

The coefficient of x in the expansion of the following is (x+3)^3 a) 1 b) 3 c) 18 d) 27 e) 9

Answer 1

d) 27

Explanation:

The expanded form of (a+b)³ is ...

(a +b)³ = a³ +3a²b +3ab² +b³

When we are expanding (x +3)³, the x-term is ...

3(x)(3²) = 27x

The coefficient of x in the expansion is 27.