Answer:
<em>Cathy was born in 1980 and she was 18 years old in 1998</em>
Step-by-step explanation:
<u>Equations</u>
This is a special type of equations where all the unknowns must be integers and limited to a range [0,9] because they are the digits of a number.
Let's say Cathy was born in the year x formed by the ordered digits abcd. A number expressed by its digits can be calculated as

In 1998, Cathy's age was

And it must be equal to the sum of the four digits 

Rearranging

We are sure a=1, b=9 because Cathy's age is limited to having been born in the same century and millennium. Thus

Operating

If now we try some values for c we notice there is only one possible valid combination, since c and d must be integers in the range [0,9]
c=8, d=0
Thus, Cathy was born in 1980 and she was 18 years old in 1998. Note that 1+9+8+0=18
 
        
             
        
        
        
Answer:look at the picture below 
Step-by-step explanation:
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The distance are
a. 42.42
b. 15. 52
<h3>How to solve for the distance</h3>
80 = 65 + <ABC
<ABC = 80 - 65
= 15
Through the use of sine rule we would have 
By using sine rule,
Sine 15/a = sine 135/b = 
sin 30/30.
Next we have to solve b by cross multiplying
b = (30× sin135) / sin 30
= 21.21/0.5
b = 42.42 km
Also, the value of a will be:
= (42.42 × sin 15) / sin 135
= 10.98/0.7071
= 15.52
Read more on bearing here: 
brainly.com/question/15221233
#SPJ1
 
        
             
        
        
        
If you're talking about the second part of the question where it asks you which facts you included in your answer, you can choose any of them and it will be counted right.