Find the coefficient of the term involving `a^2b^5` in the expansion of `(a-2b)^4 (a+b)^3`

Find the coefficient of the term involving x^10 in the expansion of (x^2-2)^11 .

Find the coefficient of the term involving x^2 in the expansion of (3x-1/x)^6 .

Find the coefficient of a^(2)b^(3)c^(4)d in the expansion of (a-b-c+d)^(10) .

Find the coefficient of (A) x^9 (B) the term independent of x in the expansion of (x^2 - 1/(3x))^9 .

Write and simplify the term involving a^2b^5 in (a-2b)^4 (a+b)^3 .

Find the coefficient of a^-6 b^4 in the expansion of (1/a-(2b)/3)^10 .

Find the coefficient of a^5 b^7 in (a - 2b)^12 .

Find the coefficient of a^4 in the expansion of the product (1+ 2a)^4 (2-a)^5 .

Sum of coefficients of expansion of B is 6561 . The difference of the coefficient of third to the second term in the expansion of A is equal to 117 . The ratio of the coefficient of second term from the beginning and the end in the expansion of B , is