Question

Find the 4th term of (x-y)12

Answer 1

-66 x^9 y^3

Explanation:

(r + 1)th term of (a + b)^n = nCr a^(n-r) b^r

so the 4th term of (x - y)^12

= 12C2 x^(12-3) (-y)^3

= 66 x^9 (-y)^3

= -66 x^9 y^3 (answer)