Answer:
Option (3)
Step-by-step explanation:
In a right triangle,
Cosine rule →
Sine rule → 
In the given triangle,
By cosine rule,


Or cos(h°) = z ÷ x
Therefore, Option (3) will be the answer.
https://www.wolframalpha.com/
Answer:
x=4, y=2
Step-by-step explanation:
2x - y = 6
x + y = 6
Add these together to eliminate y
2x - y = 6
x + y = 6
-----------------
3x = 12
Divide by 3
3x/3 = 12/3
x=4
But we still need y
x+y =6
4+y =6
Subtract 4 from each side
4+y-4 = 6-4
y=2