1. ## Binomials Problem

so i understand this entire problem and did manage to solve for r on my own except i don't understand the final answer.

3^3 = 27 not 2268

lol is the answer wrong or am I doing something wrong at this oint?

thank you very much for helping me!

2. $T_4=C_9^3\cdot 3^3=84\cdot 27=2268$

3. wait how do you get the 84?

4. Originally Posted by juliak
wait how do you get the 84?
$C_9^3=\dfrac{9\cdot 8\cdot 7}{1\cdot 2\cdot 3}=84$