I think this is right. Hope it helps
Answer:

Step-by-step explanation:
We are given a triangle
whose sides are
a=12
b=8
c=13
Since, c is largest among them
So, angle C must be largest angle
we can find angle C
we can use law of cosine formula

now, we can plug values


now, we can find angle
we get

Your answer is going to be fifteen plus r
Answer:
-5x + 0y = -11
The y terms are eliminated
Step-by-step explanation:
- 4x – 2y = -2
X - 2y = 9
We want to subtract the second equation from the first
Distribute a minus sign to all the terms in the second equation
- 4x – 2y = -2
X - 2y = 9
= (-5x + 0y = -11)