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1) How many terms are there in the expansion of [tex](a+3b-2c-d)^8[/tex] before like terms are combined?

[tex]4^8[/tex]

2) How many terms are there after like terms are combined?

[tex]_8C_4=70[/tex]

3) What is the coefficent of [tex]a^2b^3cd^2[/tex]?

[tex](_8C_2)( _6C_3)( _3C_1)( _2C_2) (3^3)(2^1)=90720[/tex]

4) What is the coefficent of [tex]ac^4d^3[/tex]?

[tex](_8C_1)(_7C_4)(_3C_3)(2^4)=1225[/tex]

5) In the expansion of [tex](a+x+x^2)^5(a+x)^4[/tex], what is the coefficent of [tex]a^6x^3[/tex]?

I don't really know where to start here but just to show everyone that I am trying this is what I have so far.

I know there are a total of 9 a's in all the factors. So I would have something like [tex](_9C_6)(_3C_?)[/tex] where the ? is what I don't know for sure.

6) What is the coefficient of [tex]a^7x^5[/tex]?

Same situation as above

I appericate any help. On the questions I have already answered I would like to know if your answers agree with mine or if I have made any mistakes. Thanks

Jeremy