Answer:
Using Pythagorean theory : a²+9²=15²
=> a²=225-81=144
=> a = √144 = 12
Step-by-step explanation:
Answer:

Step-by-step explanation:

Hope this helps!
Answer:
20
Step-by-step explanation:
$8.25
The first 5 checks are free so you can subtract the 5 from 18 which is 13. Then you multiply 13 & .25 which is equal to $3.25 and then you just add the $5