Answer:
To solve this problem, you need to use the distributive property, which states that for any two numbers a and b, and for any numbers x and y, (a + b) * x = ax + bx and x * (a + b) = xa + xb.
Applying the distributive property, we have:
(-5i)(7 + i) = (-5i) * 7 + (-5i) * i
= -35i + (-5i) * i
Now, you need to use the fact that i * i = -1:
(-5i)(7 + i) = -35i + (-5i) * i
= -35i + (-5) * (-1)
= -35i - 5
= -40i - 5
So the final result is -40i - 5.