Which properties are used to add these complex numbers? check all that apply. (4+3i)+(8+2i)=(4+8i)+(3i+2i)=12+5i a. associative property b. commutative property c. distributive property d. none of the above

Properties used here are:

A Associative property

B Commutative property.

Step-by-step explanation:

Given the expression:  

Using associative property:

Using commutative property:  

            [Using associative property]

Simplify:

  21.3

step-by-step explanation:

multiplying the given equation by c/sin(25°), we get

  c = 9/sin(25°) ≈ 21.2958 ≈ 21.3

we assume "c" is the length of ab, the side opposite angle c in triangle abc.

4444444444444 i think