It is known that the fourth binomial coefficient of the expansion of [(a-2b) to the nth power] is the largest, then the sum of the coefficients of the expansion is

It is known that the fourth binomial coefficient of the expansion of [(a-2b) to the nth power] is the largest, then the sum of the coefficients of the expansion is

Because the fourth term of the expansion of (a-2b) ^ n is the largest, and the meaning is n = 6, the habit sum of the expansion of (a-2b) ^ 6 is (3 ^ 6 + 1) × 2

If the absolute value of the square y n-3 of - 2 parts ax is the monomial of X and y, and the coefficient is 4 points system 5, and the degree is 4, the value of a and N can be obtained

If the power of the absolute value of n-2 of the cube y of - 2 parts ax is the monomial of XY, and the coefficient is 5 / 4, and the degree is 7, try to find the value of a, n

Then the value of n is 7 or - 1
Coefficient 5 / 4 = - A / 2, then a = - 5 / 2