What is the third term of (x - 3y)^8 ?

Question

can some one do it while explaining it please?

Answer 1

Binomial Theorem:

(x-3y)^8 = x^8 -(8C1)x^7 (3y) + (8C2) x^6 (3y)^2-......

The third term is

8C2 (x^6) (3y)^2

8C2 = 8 x 7 / 2 x 1 = 28

x^6

(3y)^2 =9y^2

(28) x^6 (9y^2) =252 x^6y^2

Answer 2

(x - 3y)^8

8C0 X^8 (-3y)^0 + 8C1 X^7 (-3y)^1 + 8C2 X^6 (-3y)^2 +.......

this is 3 terms only....  

Answer 3

Using pascal's triangle and a little knowledge, the third term of (a + b)^8 is 28a^6b^2.

Substituting, the answer is

28*x^6*(-3y)^2 = 252x^6y^2

Answer 4

Terms are always separated by addition. So what you need to do is use the binomial expansion on that, simplify everything, then rewrite it all in descending order, then find the third term from the left.