Answer:
see explanation
Step-by-step explanation:
given 
To rationalise multiply the numerator/denominator by the conjugate of the denominator
the conjugate of 3 + 7i is 3 - 7i, hence

distribute the numerator/denominator
=
[ note that i² = - 1 ]
= 
= 
=
+
i
=
+
i ← in standard form
Answer:
23
Step-by-step explanation:
In this question, we want to evaluate the expression "9z-4" for z=3.
This means, we want to calculate the result when we substitute the z in this expression for 3.
So we have: 9(3)-4, which is equal to 23.
Let me know if this helps!
A. 9.3 x 10^7 miles
B. 4 x 10^-2 inches
C. 5.89248 x 10^12 inches
D. 1.47312 x 10^14 fireflies