Question

Coefficient of x^2 in the expansion of (x – 3)^3
(a)1
(b) -9
(c) 6
(d)3

Answer 1

Answer:

3. expand the formula. you will get x3+y3+3x2y+3xy2

Answer 2

Answer:

-9

Step-by-step explanation:

The general expansion of (x-a)ⁿ is (ⁿC₀xⁿ a⁰+ ⁿC₁ x^(n-1) a¹+.......+ⁿCₙ x⁰ aⁿ)

So the given expansion is (x-3)³ = ³C₀x³+³C₁x²(-3)+....

Here the coefficient of x² is ³C₁(-3)= -9