Step-by-step explanation:
With each draw, the probability of selecting a green marble is 2/3 and the probability of selecting a yellow marble is 1/3.
To pick two of the the same color, they can either pick green twice or yellow twice.
P = (2/3)(2/3) + (1/3)(1/3)
P = 5/9
To pick two different colors, they can either pick green first then yellow, or yellow first then green.
P = (2/3)(1/3) + (1/3)(2/3)
P = 4/9
Expected value for Derek is:
D = (5/9)(-1) + (4/9)(1)
D = -1/9
The expected value for Mia is:
M = (5/9)(1) + (4/9)(-1)
M = 1/9
Answer:
yep thats correct
Step-by-step explanation:
Y-2x=6 => y=6+2x
Y+2x=0
(6+2x) + 2x = 0
6 + 4x = 0
4x= 6
X=6/4
X= 3/2
Y=6+2x
Y=6+2. 3/2
Y= 6 + 3
Y=9
Check: y-2x=6
9-2. 3/2 = 6
9 - 3 = 6
The easiest way to solve this is by elimination.
3x - y = 6
6x + y = 21
Since you have a negative and positive y with the same coefficients (1), they cancel, and you add the other terms so it would look like:
9x = 27
Then solving for x leaves you with x = 3
Then you take the x value of three and plug it into to either of the equations, so
3(3) - y = 6
9 - y = 6
subtracting 9
-y = -3
then dividing by -1
y = 3
so the solution is x = 3 y = 3 or (3,3)
