Answer:
x = -7
, y = 0
Step-by-step explanation:
Solve the following system:
{4 x + 5 y = -28 | (equation 1)
-4 x - 7 y = 28 | (equation 2)
Add equation 1 to equation 2:
{4 x + 5 y = -28 | (equation 1)
0 x - 2 y = 0 | (equation 2)
Divide equation 2 by 2:
{4 x + 5 y = -28 | (equation 1)
0 x - y = 0 | (equation 2)
Multiply equation 2 by -1:
{4 x + 5 y = -28 | (equation 1)
0 x+y = 0 | (equation 2)
Subtract 5 × (equation 2) from equation 1:
{4 x+0 y = -28 | (equation 1)
0 x+y = 0 | (equation 2)
Divide equation 1 by 4:
{x+0 y = -7 | (equation 1)
0 x+y = 0 | (equation 2)
Collect results:
Answer: {x = -7
, y = 0
Remark
You need to start with three facts.
x and y are complements which means that x + y = 90
Sin(x) = cos(90 - x)
<CPN = <DPN Definition of a bisector.
From the 3 facts above, we can gather than
CPN + y = 90
Therefore the cos of CPN = Sin(y)
Answer:
22
Step-by-step explanation:
11 x 2 = 22
22 teams played
Answer:
The polygon has 3 sides ( a triangle).

Explanation:
The sum of the angles of a polygon can be written as;

where n is the number of sides of the polygon.
Given that the sum of the angles in the polygon is 180 degree;

Therefore, the polygon has 3 sides ( a triangle).
Answer:
25
Step-by-step explanation:
I understand this as
. This is equal to 1 * 25 = 25.