Step-by-step explanation:

Now for another

Hope it will help :)❤
5.
Let x be the age of the father and y be the age of the son. As of today, he's 3 times older, so we have 
10 years ago their ages were, respectively, x-10 and y-10, and the father was 5 times older: 
So, we have the system

Using the first equation, we can substitute every occurrence of "x" with "3y" in the second equation:

So, the son is 20 years old, which means that the father is 60 years old.
Indeed, 10 years ago they were 10 and 50 years old, so the father was 5 times older.
6.
Let x be the age of the grandfather and y the age of the granddaughter. We know that the grandfather is 10 times older: 
He also is 54 years older: 
Again, if we substitute x=10y in the second equation we have

Answer:
Option P √2.5²-1.2²
Step-by-step explanation:
a = distance between Toby's House and the playground = 1.2 inches
b = distance between the playground and Toby's Friend's House = unknown
c = distance between Toby's House and Toby's Friend's House = 2.5 inches
Use the Pythagorean Theorem to calculate the side length of b:
a²+b²=c²
b²=c²-a²
b=√(c²-a²)
b=√(2.5²-1.2²)
Therefore, option P is correct.
It’s B ————————————………………