SOLUTION: which of the following could be a term in the expansion of (x+y)^7 1. 35xy^7 2. 35x^8 y^-1 3. 35 x^7 y 4. 35 x^2 y^8 5. 35 x^3 y^4

Algebra ->  Equations -> SOLUTION: which of the following could be a term in the expansion of (x+y)^7 1. 35xy^7 2. 35x^8 y^-1 3. 35 x^7 y 4. 35 x^2 y^8 5. 35 x^3 y^4      Log On


   



Question 39892: which of the following could be a term in the expansion of (x+y)^7
1. 35xy^7
2. 35x^8 y^-1
3. 35 x^7 y
4. 35 x^2 y^8
5. 35 x^3 y^4

Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Only choice 5 is possible.
The coefficient, found from Pascal's Triangle (or other means) of both the x^7y and xy^7 terms are both 7...
The powers of x and y must add to seven...
The only choice left is choice 5.