The answer is 6.601, and therefore, the second option.
Answer:
x ≈ 20.42, y ≈ 11.71
Step-by-step explanation:
Using the cosine ratio on the right triangle on the right, that is
cos20° =
= 
Multiply both sides by y
y × cos20° = 11 ( divide both sides by cos20° )
y =
≈ 11.71
Using the sine ratio on the right triangle on the left, that is
sin35° =
=
= 
Multiply both sides by x
x × sin35° = 11.71 ( divide both sides by sin35° )
x =
≈ 20.42
Hello,
N is closed for an opération(µ) means that
a,b ∈ N : a µ b ∈N (i suppose so)
Answer (1) ex 2/3 ∉ N
Answer (4) ex 2-3 ∉ N
∀ a,b ∈ N: a+b ∈N is true ; not a answer.
∀ a,b ∈ N: a*b ∈N is true ; not a answer.