Answer:
the awnswer is a = 7 + c
Step-by-step explanation:
You want to know the factor by which 3 2/3 is multiplied to get 7 1/3.
1. You can estimate that it is 2 from 7/3 ≈ 2, then check by multiplication to see if that is right.
.. 2*(3 2/3) = 6 4/3 = 7 1/3 . . . . 2 is the correct factor.
2. You can divide 7 1/3 by 3 2/3 to see what the factor is.
.. (7 1/3)/(3 2/3) = (22/3)/(11/3) = 22/11 = 2 . . . . 2 is the factor Earl used.
3. You could see how many times you can subtract 3 2/3 from 7 1/3.
.. 7 1/3 -3 2/3 = (7 -3) +(1/3 -2/3) = 4 -1/3 = 3 2/3 . . . . . subtracting once gives 3 2/3
.. 3 2/3 -3 2/3 = 0 . . . . . . subtracting twice gives 0, so the factor is 2.
4. You could add 3 2/3 to see how many times it takes to get 7 1/3.
.. 3 2/3 +3 2/3 = (3 +3) +(2/3 +2/3) = 6 +4/3 = 7 1/3
We only need to add two values of 3 2/3 to get 7 1/3, so the factor is 2.
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We have shown methods using multiplication, division, subtraction, addition. Take your pick.
Let the reduced price be x
If he paid for 6 rounds, he paid 1 round at full price of $19 and 5 rounds at reduced price:
19 + 5x = 59
5x = 59 - 19
5x = 40
x = 40 ÷ 5
x = 8
The reduced price is at $8 per round.
You can do C(6,2) which gives
which is
15!
You can show that 
by constructing a triangle.
Take two points, O(0, 0) and A(1, 0), and let B be the point on the unit circle such that the angle between the line segments OA and OB is 
radians.
Since both A and B lie on the circle, the line segments OA and OB both have length 1 (same as the circle's radius). We finish constructing the triangle by connect A and B.
Since OB and OA have the same length, triangle OAB is isosceles, but more than that, it's also equilateral. Why? Because the interior angles of any triangle always add to 
radians. We know one of the angles is radians, which leaves a contribution of 
radians between the remaining angles A and B. Angles A and B must be congruent (because OAB is isosceles), which means they also have measure radians.
Next, draw an altitude of the triangle through point B, and label the point where it meets the "base" OA, C. Since OAB is equilateral, the altitude BC is also a perpendicular bisector. That means OC has length 
, and by definition of 
we have
