Answer:
x=5
Step-by-step explanation:
3x + 45 = 60
-45 -45
3x = 15
15 ÷ 3= 5
x= 5
-I hope this helps have a great day!
Answer:
Step-by-step explanation:
Using the distance formula,

So the perimeter is 
I dont know this one sorry
Answer:
The answer is a. 21.
Step-by-step explanation:
We solve this question by using Pythagoras theorem to relate the sides of a right angled triangle.
Here,
Hypotenuse of the given triangle(c)=75
Two sides of right angled triangle are:
a=72
b=?
Then,
for a given right angled triangle abc,
Using Pythagoras theorem,

Squaring on both sides,

or,
or, 
or,
or,
∴
So, the value of b is obtained to 21 by the use of Pythagoras theorem.