MATHS C2 HELP?!! BINOMIAL EXPANSION

[Blueberryavalanche47]

PLEASE IF ANYONE CAN EXPLAIN HOW TO SOLVE THIS I WILL BE SOOOOO HAPPY AND GRATEFUL!

So here it is:
When (1- 3/2x)^p is expanded in ascending powers of x, the coefficient of x is -24.
a) find the value of p
b) find the coefficient of x^2
c) find the coefficient of x^3

 

[Ysph06]

(1- 3/2x)^p is in the form ( 1 + x ) ^ n

( 1 + x ) ^ n can be expanded in to format = 1 + nx + [ n(n-1)x^2 ] / 2 + [ n(n-1)(n-2)x^3 ] / 6 + ......

here, n=p and x= -3/2x
Substitute these and equate the coefficient of x term to -24 to find p
Substitute P in to the x^2 and x^3 terms to get their coefficient