Explanation:
To find the coefficient of x² in the expansion of (1+ax)⁴(a-2)³, we can use the binomial theorem. The binomial theorem states that for any two numbers a and b and any non-negative integer n, the expansion of (a+b)^n is given by the sum of the terms:
(a+b)^n = C(n,0)a^n * b^0 + C(n,1)a^(n-1) * b^1 + C(n,2)a^(n-2) * b^2 + ... + C(n,n)a^0 * b^n
where C(n,k) = n! / (k!(n-k)!) is the binomial coefficient.
We can apply the binomial theorem to find the coefficient of x² in the expansion of (1+ax)⁴(a-2)³:
(1+ax)⁴(a-2)³ = (1+4ax+6(ax)²+4(ax)³+(ax)⁴)(a-2)³ = a^3 - 6a^2 + 12a - 8 + 6(ax)² + ...
So the coefficient of x² in the expansion is 6.