Answer:
Step-by-step explanation:
They are closed under addition, subtraction and multiplication.
Answer:
1) 
.
2) 
years
Step-by-step explanation:
Let Hanna's sister be 
years old.
Then Hanna will be 
years old.
The sum of their ages will be 
years.
The statement "no more than 18" means the sum of their ages is less than or equal to 18.
The required inequality is;
.
2)
The inequality we just found is
.
We simplify to get;
.
we divide both sides by 
to get;
.
Therefore the oldest age Hannah's sister can be is years
Answer:
Freddie would have walked 25 miles after 12 and a half hours.
Step-by-step explanation:
Given that Freddie is walking at a constant speed, and after 2 hours he walked 4 miles, while after 4 hours he walked 8 miles, to determine how long he walked 25 miles, the following calculation must be performed:
4/2 = Miles per hour
2 miles per hour
2X = Y
2X = 25
X = 25/2
X = 12.5
Therefore, Freddie would have walked 25 miles after 12 and a half hours.
Answer:
k=45
Step-by-step explanation:
its an isosceles triangle, so k=45
to check it, 45+45+90=180
