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

-66 x^9 y^3

Step-by-step 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)