Question

Find the coefficient of fourth term of (-x -3)^5

Answer 1

Answer:

-270

Step-by-step explanation:

Here, we want to know the coefficient of the fourth term.

The coefficients according to pascal triangle for the expansion is 1 5 10 10 5 1

So the expansion looks as follows;

1[(-x)^5(-3)^0] + 5[(-x)^4(-3)^1)] + 10[(-x)^3(-3)^2) + 10[(-x)^2(-3)^3] + ...........

So the fourth term we are dealing with is

10[(-x)^2(-3)^3)]

So the value here is

10 * x^2 * -27

= -270 x^2

So the coefficient is -270