34.5=4h+7c
(34.5-7c)/4=h
Put h= (34.5-7c)/4 into another equation
30.5=8h+3c
30.5=2(34.5-7c)+3c
30.5=69-14c+3c
11c=38.5
c=38.5/11
Put c=38.5/11 into one of the equations
to calculate the h.
Let's solve for x:
100x=1000
Divide by 100
x=10
You should expect to win 10 times.
For it to be a solution, it has to satisfy both inequalities...
subbing in (-4,-1)
2x + y < -5 -x + y > 0
2(-4) - 1 < - 5 -(-4) - 1 > 0
-8 - 1 < -5 4 - 1 > 0
-9 < -5.....true 3 > 0....true
solution is (-4,-1)
Note that
108° = 90° + 18°
so
sin(108°) = sin(90° + 18°) = sin(90°) cos(18°) + cos(90°) sin(18°) = cos(18°)
Then
sin²(108°) + sin²(18°) = cos²(18°) + sin²(18°) = 1
by the Pythagorean identity.
