1) write the expression in standard form.

7/ 3-15i

a. 7/78 - 35/78i

b. -7/78 - 35/78i

c. 7/78 + 35/78i

d. -7/78 + 35/78i

2) find the product of the complex number and its conjugate.
1 + 3i

a. 1 + 9i

b. 10

c. -8

d. 1 - 9i

 A complex number is a real number, an imaginary number or a number with both real and imaginary number. Its standard form is:

a + bi

For the expression, 7/ 3-15i

(7/ 3-15i) (3+15i)
21 - 105i / (234)
7/78 - 35/78i

Therefore, the correct answer is option A.