Answer:
Step-by-step explanation:
This is an equation for which you need to solve for the value of the missing angle beta.

sin(15) has a decimal answer that you will find on your calculator. Finding that value makes this equation then
cosβ = .2588190451
Now use the 2nd button and then the cos button to find the angle that has a cos of that decimal. When you hit 2nd then cos, you should see this on your screen:
cos⁻¹ (
After that open parenthesis, enter you decimal then hit the enter button to find the angle. You should get 75, which is Choice B.
Answer:
y = -1/2x +6
Step-by-step explanation:
We can use the slope intercept form of a line
y = mx+b where m is the slope and b is the y intercept
y = -1/2x +b
Substitute the point into the equation
9 = -1/2 (-6) +b
9 = 3+b
9-3 =b
6 =b
y = -1/2x +6
Answer:
B. 1/2
Step-by-step explanation:
Make 9 an improper fraction, then multiply by -5/6.
-5/6 times 9/1 = -45/6.
-45/6 cannot be simplified, so you make it a mixed number.
-7 1/2.
Add the 7 to -7 1/2 and that cancels out to 1/2
No derivation at x=3 .
only at x=3
Given equation is y=2x+7 and 
Let's simplify the 2nd equation
before we can start graph so that calculation will be easy

multiply both sides by 2 to cancel out fractions

y=2x+7
which is exactly same as the first equatoin so graph of both will be exactly same and solution will be infinitely many solutions.
y=2x+7 has y-intercept 7 so first point will be (0,7). Slope is 2 so rise 2 unit up then 1 right and graph the new point.