It is 180 because it rotates
Last one of the first one try the last one first
We have the following given
p1 - probability for outcome 1
p2 - probability for outcome 2
p3 - probability for outcome 3
v1 - amount of money that you will win or lose for outcome 1
v2 - amount of money that you will win or lose for outcome 2
v3 - amount of money that you will win or lose for outcome 3
Therefore,
p1v1 + p2v2 + p3v3 is the average money you win or lose in playing the game.
To factor quadratic equations of the form ax^2+bx+c=y, you must find two values, j and k, which satisfy two conditions.
jk=ac and j+k=b
The you replace the single linear term bx with jx and kx. Finally then you factor the first pair of terms and the second pair of terms. In this problem...
2k^2-5k-18=0
2k^2+4k-9k-18=0
2k(k+2)-9(k+2)=0
(2k-9)(k+2)=0
so k=-2 and 9/2
k=(-2, 4.5)