Let me extract and solve the problems from the image you've uploaded. Here are the questions I see:

Question 17:
Hasil dari $(2 + 3i) + (4 - 5i)$ adalah:
A. $2 - 6i$
B. $3 - 5i$
C. $4 - 4i$
D. $5 - 3i$
E. $6 - 2i$

Solution for Question 17:
We add the real and imaginary parts separately:
Real part: $2 + 4 = 6$
Imaginary part: $3i + (-5i) = -2i$
So, the result is $6 - 2i$.
Answer: E

Question 18:
Bilangan yang bagian riil = 10 dan bagian imajiner = $3i$ adalah:
A. $10 + 3i$
B. $10i + 3$
C. $10i - 3i$
D. $10 - 3i$
E. $10i - 3$

Solution for Question 18:
The real part is 10, and the imaginary part is $3i$, so the number is $10 + 3i$.
Answer: A

Question 19:
Hasil dari $3(4 - 5i)$ adalah:
A. $7 - 5i$
B. $12 - 15i$
C. $15 - 7i$
D. $12 - 5i$
E. $12i - 5i$

Solution for Question 19:
Distribute the 3 over both terms:
Real part: $3 \times 4 = 12$
Imaginary part: $3 \times (-5i) = -15i$
So, the result is $12 - 15i$.
Answer: B

Question 20:
Hasil dari $(2i - 4) - (3 - 7i)$ adalah:
A. $7 + 9$
B. $-7 + 9i$
C. $7i + 9$
D. $7 - 9i$
E. $7i - 9$

Solution for Question 20:
Distribute the negative sign:
$(2i - 4) - (3 - 7i) = 2i - 4 - 3 + 7i$
Combine real and imaginary parts:
Real part: $-4 - 3 = -7$
Imaginary part: $2i + 7i = 9i$
So, the result is $-7 + 9i$.
Answer: B

Would you like further details or explanations on any of the problems? Here are some related questions to expand on this topic:

1. How do you multiply two complex numbers like $(2 + 3i)(4 - 5i)$?
2. Can you explain how the distributive property applies to complex numbers?
3. What is the geometric interpretation of adding two complex numbers?
4. How can you find the conjugate of a complex number, and why is it useful?
5. How do you calculate the modulus (magnitude) of a complex number like $3 + 4i$?

Tip: When subtracting complex numbers, remember to distribute the negative sign across both the real and imaginary parts!