Simplifying the Expression (d^2 + 6d + 9) + (d^3 + 6d + 9)
This article will guide you through simplifying the given expression, (d^2 + 6d + 9) + (d^3 + 6d + 9).
Understanding the Expression
The expression consists of two separate polynomials:
 (d^2 + 6d + 9) is a quadratic trinomial.
 (d^3 + 6d + 9) is a cubic trinomial.
These polynomials are being added together.
Combining Like Terms
To simplify, we combine terms with the same variable and exponent.

Identify like terms:
 d^3 terms: Only the term d^3 is present.
 d^2 terms: Only the term d^2 is present.
 d terms: We have 6d and 6d.
 Constant terms: We have 9 and 9.

Combine the coefficients of like terms:
 d^3 term: d^3
 d^2 term: d^2
 d term: 6d + 6d = 12d
 Constant term: 9 + 9 = 18
Simplified Expression
Combining all the terms, the simplified expression is:
d^3 + d^2 + 12d + 18
This is the most simplified form of the given expression.