What is the third term in the expansion of (x + 2)7?

Question

anonymous · Answer

(x+2)^7

cathyangs · Answer

have you heard of pascal's triangle?

anonymous · Answer

yes put i have to clue how to use it

cathyangs · Answer

1
11
121
1331
14641
15 10 5 1
1 6 15 15 6 1
1 7 21 30 21 7 1
____^ that right there. 21 is the coefficient. The x's power starts at 7, and decreases by one each term. The 2 does the opposite. In the seventh row, the third number is the coefficient of this term. so x^5*2^3*21 is 168*x^5
do you get it, or would you like me to explain a bit more?

anonymous · Answer

explain a little more please?

cathyangs · Answer

*oops. did my math wrong. it's x^5*2^2*21, which equals 84*x^5

cathyangs · Answer

ok...so you understand pascal's triangle, correct?

anonymous · Answer

i get it now i got confused with your math but now i understand thank you sooo much

cathyangs · Answer

ok. I'm happy to help! :D