Answer:
The required expression is [tex]3x^3+6x^2+9x+1[/tex].
Step-by-step explanation:
Consider the provided information.
Let x is the variable used in the expression.
The expression should contain 4 terms, thus the powers of x will be:
[tex]x^3, x^2, x^1=x, x^0=1[/tex]
Now it is given that the coefficients are 3, 6 and 9.
Assign the coefficients 3,6, and 9 with the above power as shown:
[tex]3x^3+6x^2+9x^1+1[/tex]
[tex]3x^3+6x^2+9x+1[/tex]
Note: There can be infinite many possible expression with four terms containing the coefficients 3,6, and 9
Hence, the required expression is [tex]3x^3+6x^2+9x+1[/tex].