When performing addition and multiplication with constant numbers, we treat
i as we would treat any variable x in an expression, with the same rules and properties of addition and multiplication.
1)

2)
Distribute 7+7i over 6 and 7i:

collecting similar terms, and substituting

with -1 we have:
42+91i-49=-7+91 i
3)
The conjugate of a complex number
a+bi is
a-bi;
the conjugate of
1+3i is
1-3i.
Thus, using the difference of squares formula we have

4)
To write a rational expression ( with a complex number in the denominator) in the standard form, we multiply by the conjugate of the denominator both the numerator and the denominator:


simplifying by 9, the complex number is finally written as

5)
2 complex numbers a+bi, and c+di are equal only if a=c, and b=d. (Where a, b, c, d are real numbers.)
Thus, x=5, and y=3 is the solution to the equation.
Answers:
1) A
2) A
3) B
4) D
5) (x, y) =( 5, 3)