In trigonometry, we start from the point (1,0), so this is the 0-degree point. Then, we start rotating counter clockwise along the unit circle.
Note that rotating 180 or -180 degrees is actually the same, because you travel half the circumference clockwise or counter clockwise. In both cases, you start from the rightmost point of the circle, (1,0), and arrive at the leftmost point, (-1,0).
Now, for every point (x,y) on the unit circle, given by a certain angle
, we have

So, in this case, the angle of -180 is associated with the point (-1,0), and thus we have

The top two answers are equivalent, while the bottom one is not. You would use distributive property in the parentheses. If both expressions are the same, they are equivalent
Let e=erasers and p=pencils. So we know the total amount of erasers plus pencils sold is equal to 220. Therefore,

We also know the cost of erasers and pencils totaled to $695 in earnings and so:

and so those are your two equations.
Answer:
meg spen $18 and betting spent $90
Step-by-step explanation:
Answer:
£210
Step-by-step explanation:
Given that :
Visa cost = £2300
7% charge of visa price = (0.07 * £2300) = £161
Total cost = £(161 + 2300) = £2461
Amount to be saved per month = £2461 / 12 = £205.08333
= £210 (nearest £10)