Apply the Distributive Property to simplify the expression. (2+i)(4+5i)

1 answer

To apply the Distributive Property to simplify the expression \( (2+i)(4+5i) \), we can use the distributive property (also known as the FOIL method for binomials). The expression can be expanded as follows:

\[ (2+i)(4+5i) = 2 \cdot 4 + 2 \cdot 5i + i \cdot 4 + i \cdot 5i \]

Now, calculate each term:

  1. \( 2 \cdot 4 = 8 \)
  2. \( 2 \cdot 5i = 10i \)
  3. \( i \cdot 4 = 4i \)
  4. \( i \cdot 5i = 5i^2 \)

Since \( i^2 = -1 \), we can simplify \( 5i^2 \):

\[ 5i^2 = 5(-1) = -5 \]

Now, put all the calculated parts together:

\[ 8 + 10i + 4i - 5 \]

Combine the like terms (\( 8 - 5 \) and \( 10i + 4i \)):

\[ 8 - 5 = 3 \] \[ 10i + 4i = 14i \]

So, the final simplified expression is:

\[ 3 + 14i \]

Thus, the simplified expression is

\[ \boxed{3 + 14i} \]