Answer:
12.56 mm²
Step-by-step explanation:

Plug the given values into the area equation

Therefore, the area of the circle is 12.56 mm².
I hope this helps!
Since you need an isolated variable to use the substitution method, we need to re-arrange one of the equations. This will probably be easiest to do with the first one.
Add 5y to both sides of the first equation.
x=10+5y
Now, in the second equation, put in 10+5y in any spot that has an x.
2(10+5y)-10y=20
Distribute the 2 to both numbers in the parenthesis.
20+10y-10y=20
Combine like terms.
20=20
This means that the two equations are actually the same. You can see this if you multiply the whole first equation by 2
2(x-5y=10)
2x-10y=20, which is the same as the second equation. Therefore, the two equations are actually the same one.
Solution
Step 1
The opposite angles of a parallelogram are equal:
Step 2

The equation is made true by the opposite angles theorem is
85 + y = 3y - 15
or
y = 50
14. The distance between the two points is 14.866.
Distance can be calculated with the following formula:
d=√(x₂-x₁)²+(y₂-y₁)²
d=√(12-2)²+(5-(-6))²
d=√10²+11²
d=√100+121
d=√221
d=14.866
15. The distance between the two points is 20.248.
Use the same formula to find the distance.
d=√(x₂-x₁)²+(y₂-y₁)²
d=√(4-(-3))²+(12-(-7))²
d=√7²+19²
d=√49+361
d=√410
d=20.248