The expression is .

Product property of real numbers is .

The FOIL method can be used to multiply the complex numbers.

Foil method: the product of two binomials is the sum of the products of the First terms, the Outer terms, the Inner terms and the Last terms.

The word FOIL is an acronym for the four terms of the product.

Multiply the complex numbers using FOIL method

                      (Multiply: )

Combine like terms using distributive property: ac + bc = (a + b)c.

                           (Add: 4 + 1 = 5)

                     (Substitute the imaginary unit value )

                              (Product of two same signs is positive)

Apply commutative property of addition: a + b = b + a.

                                          (Apply additive inverse property: )

Distribute terms using distributive property: .

                            (Multiply: )

                     (Substitute the imaginary unit value )

                              (Product of two same signs is positive)

The simplified expression is .