Answer:
sin(x) = 5/13
cos(y) = 5/12
Therefore, sin(x) = cos(y)
Step-by-step explanation:
Trig ratios:

where
is the angle, O is the measure of the side opposite the angle, A is the measure of the side adjacent to the angle and H is the hypotenuse, of a right triangle
We have been given the measures of the two legs, so we can find the measure of the hypotenuse by using Pythagoras' Theorem 
(where a and b are the legs and c is the hypotenuse of a right triangle)

Now we can use the trig ratios:


Therefore, sin(x) = cos(y)
1,-7 would be the answer I believe
m∠AOC = m∠AOB + m∠BOC
We have m∠AOC = 19°, m∠AOB = 4x - 15 and m∠BOC = 2x + 10. Substitute:
19 = (4x - 15) + (2x + 10)
19 = (4x + 2x) + (-15 + 10)
19 = 6x - 5 <em>add 5 to both sides</em>
24 = 6x <em>divide both sides by 6</em>
4 = x
m∠BOC = 2x + 10 → m∠BOC = 2(4) + 10 = 8 + 10 = 18
m∠AOB = 4x - 15 → m∠AOB = 4(4) - 15 = 16 - 15 = 1
<h3>Answer: c. m∠BOC = 18°, m∠AOB = 1°</h3>
The answer to that would be 0

You divide -6 and -3

Because the exponents are both negative, you make them positive and change the position (the exponent which is at the denominator is now at the numerator and viceversa)


You divide the exponents (so 2-1)
2*10 = 20