OpenStudy (anonymous):

Find the specified nth term in the expansion of the binomial. (Write the expansion in descending powers of x.) (x - 2y)^12, n = 6

6 years ago
OpenStudy (savvy):

since nCr starts from r=0 and goes till r=n there are n+1 terms....clearly 1st term is when r=0, second when r=1 and so on....similarly 6th term would be when r=5 which means it is [12C5]x^7(-12y)^5

6 years ago
OpenStudy (anonymous):

So would that be -25,344x^7y^5?

6 years ago
OpenStudy (savvy):

yeah if 12C5 is equal to 25,334

6 years ago
OpenStudy (anonymous):

how can I figure out what 12C5 is equal to?

6 years ago
OpenStudy (savvy):

12C5 = (12!)/[(5!)(7!)]......YOU CAN ALWAYS CALCULATE THAT....IT IS A LONG STORY THOUGH....

6 years ago
OpenStudy (anonymous):

thanks for your help

6 years ago
OpenStudy (savvy):

ANYTYM....

6 years ago