答えは

正解

d = 1 (slider from -1000 to 1000, step 1)
入力ボックス1 = Textfield(d)
n: floor(random() * 7 + 3)
a: floor(random() * 3 + 1)
b: floor(random() * 5 - 2)
f = Expand((a * x + b)^(n))
g = Expand(a * x + b)
c: floor(random() * (n - 1) + 2)
テキスト1: "$(" + (LaTeX[g]) + ")^" + (LaTeX[n]) + "$の$x^" + (LaTeX[c]) + "$の係数を求めよ．"
dd: a^(c) * b^(n - c) * Binomial[n, c]