Expanding (d + 3)^2
The expression (d + 3)^2 represents the square of the binomial (d + 3). To expand this expression, we can use the FOIL method or the square of a binomial formula.
Using the FOIL Method
- First: Multiply the first terms of each binomial: d * d = d^2
- Outer: Multiply the outer terms of the binomials: d * 3 = 3d
- Inner: Multiply the inner terms of the binomials: 3 * d = 3d
- Last: Multiply the last terms of each binomial: 3 * 3 = 9
Adding all the results together: d^2 + 3d + 3d + 9
Simplifying the expression: d^2 + 6d + 9
Using the Square of a Binomial Formula
The square of a binomial formula states that: (a + b)^2 = a^2 + 2ab + b^2
Applying this to our expression:
- a = d
- b = 3
Substituting the values: d^2 + 2(d)(3) + 3^2
Simplifying: d^2 + 6d + 9
Therefore, the expanded form of (d + 3)^2 is d^2 + 6d + 9.