If

is the variable of the horizontal axis, then you can solve for

to get the equation of the line in slope-intercept form in the

plane:

i.e. a line with slope

through the origin, which means it is contained in the first and third quadrants. Since the terminal side of

has a negative sine, the angle must lie in the third quadrant.
Because the slope of the line is

, you can choose any length along the line to make up the hypotenuse of a right triangle with reference angle

. Any such right triangle will have

, regardless of whether the angle is the first or third quadrant. But since

is known to lie in the third quadrant, and so

and

are both negative, you have
Answer:
Step-by-step explanation:
58% of 10 pounds = 0.58 × 10 pounds = 5.8 pounds
X= be coffee
Y=be donuts
Set up equations
10x+5y=16.50
5x+10y=14.25
Now multiply first equation by -2 to get a negative
(-2)10x+5y(-2)=16.50(-2)
-20x-10y=-33
Now put both equations to solve for x
-20x-10y=-33
5x+10y=14.25
___________
-15x. = -18.75
Now divide -15 bith sides to get x alone
X= -18.75/-15
X= 1.25
The cost of each coffee cup$1.25
the answer is 21/77 because you multiplied 11 by 7 to get 77, you multiply 7 by which gives you 21/77