I think 5?
These are the ages,
12, 12, 14, 15, 17,
28, 29,
40, 41, 44, 45,
50,
69
Only the people on the first row are under 19 and there are 5 people.
First. we use the Pythagorean theorem:

Add the numbers in

start simplifying


So, the leg has a length of 40 mm.
Step-by-step explanation:
5x=1-6
5x=-5
<h3> x=-1</h3>
-5(-1)-8y=2
5-8y=2
-8y =2-5
-8y=-3
<h3> y=3/8</h3>
The variable in this algebraic expression is b