Answer:
The speed of the boat in still water = 8 Km/hr
Step-by-step explanation:
Let the speed of the boat be x
According to question
(x-4)15 = (x+4)5
3x-12 = x+4
⇒x = 8 km/hr
If you're trying to say what's 90% of 63, you divide 63 by 10 which is 6.3 then times by 9 which is 56.7
This equation does not have an answer
we know that
The conjugate of a complex number is the number with equal real part and imaginary part equal in magnitude but opposite in sign
so
In this problem we have

the conjugate is equal to--------> 
therefore
<u>the answer is the option</u>
10+3i