Question 1031691
<pre>
{{{(x^4 + x^3 + x^2 + x + 1)^4}}}{{{""=""}}}

{{{(x^4 + x^3 + x^2 + x + 1)(x^4 + x^3 + x^2 + x + 1)(x^4 + x^3 + x^2 + x + 1)(x^4 + x^3 + x^2 + x + 1)}}}

The only way to get a x in that multiplication is: 

1. When the 1's in the 1st, 2nd, and 3rd parentheses are multiplied 
   by the x in the 4th parentheses, giving term 1*1*1*x = x.

2. When the 1's in the 1st, 2nd, and 4th parentheses are multiplied 
   by the x in the 3rd parentheses, giving term 1*1*x*1 = x.

3. When the 1's in the 1st, 3rd, and 4th parentheses are multiplied 
   by the x in the 2nd parentheses, giving term 1*x*1*1 = x.

4. When the 1's in the 2nd, 3rd, and 4th parentheses are multiplied 
   by the x in the 1st parentheses, giving term x*1*1*1 = x.

So the only term in x is x+x+x+x = 4x, which has coefficient 4.

Incidentally, the whole thing multiplied out is:
<font size=1>
x<sup>16</sup>+4x<sup>15</sup>+10x<sup>14</sup>+20x<sup>13</sup>+35x<sup>12</sup>+52x<sup>11</sup>+68x<sup>10</sup>+80x<sup>9</sup>+85x<sup>8</sup>+80x<sup>7</sup>+68x<sup>6</sup>+52x<sup>5</sup>+35x<sup>4</sup>+20x<sup>3</sup>+10x<sup>2</sup>+4x+1</font>

Edwin</pre>