Answer:
x = -6/5
y =7/5
Step-by-step explanation:
2x + y = - 1
x - 2y = - 4
Multiply the first equation by 2 so we can eliminate y
2(2x + y = - 1)
4x + 2y = -2
Add this to the second equation
4x + 2y = -2
x - 2y = - 4
---------------------
5x + 0y = -6
Divide by 5
5x/5 = -6/5
x = -6/5
Multiply the second equation by -2 so we can eliminate x
-2(x - 2y = - 4)
-2x+4y = 8
Add this to the first equation
2x + y = - 1
-2x+4y = 8
---------------------
0x + 5y = 7
Divide by 5
5y/5 = 7/5
y =7/5
Answer:
0.1137= 11.37%
Step-by-step explanation:
Assuming there are 365 days in one year and every people have 1 birthday, then the chance for two people to have the same birthday is 1/365 and the chance they are not is 364/365. We are asked the chance for at least one match among 44 people. The opposite of the condition is that we have 0 matches and easier to calculate. The calculation will be:
P(X>=1)= ~P(X=0) = 1
P(X>=1)=- P(X=0)
P(X>=1)=1 - (364/365)^44
P(X>=1)=1- 0.8862
P(X>=1)=11.37%
I think c .. I already took a course .. and the test had that question.. I cant remember the answer though