I'm sorry I really don't know I'm not really good with math that's why I got them brainly for other people's help because I really not that cool math and I'm homeschooled
Answer:

Step-by-step explanation:
We know

in the third quadrant 
We use a scientific calculator to find the inverse cosine of -0.9041 to find

Since this angle is not in the required quadrant we must find the other angle who has the same cosine. The required angle is equidistant from the found value from the 180 degrees angle, so our solution is

Simple...
you have: 15x+2=17
Isolate the variable (x)-->>>>
15x+2=17
-2 -2
15x=15
x=1
To check it-->>>
15(1)+2=17
17=17
Thus, your answer.
First you have to find 1/3 of the marbles. That means in the twelve marvels she has, there are three even groups. Divide twelve by three and you get four. So if each group is four, it is simple from here on out. If she started out with twelve and she lost 1/3 of them(4) it would be 12-4. You know this because lost is another for for subtract. 12-4=8. She has 8 marbles left.
Decimal form - 8.24
mixed number form - 8 1/4