Practice By Tag: Newton's Binomial Theorem

Question: 2014 Fall Midterm - 7

1 . What is the coefficient of $x^{20}y^{80}$ in the expansion of $(5x - 3y)^{100}$?

(a)

$-{100 \choose 80} 5^{20}3^{80}$

(b)

${100 \choose 80} 5^{20}3^{80}$

(c)

${100 \choose 80} 5^{80}3^{20}$

(d)

${80 \choose 100} 5^{20}3^{80}$