You need these two basic solutions and facts to find the equation of a line:
- If you know the gradient
and one point 
:
- If you know the gradient two points
:
- The slope of a line is the coefficient m when you write it in the
form - Parallel lines have the same slope
- The slopes of perpendicular lines give -1 when multiplied
We can use this list to solve all the exercises:
b)
Use the first equation to get
c)
Use the second equation to get
d) same as c)
e) We derive the slope of the line by writing it as
So, the slope is -1/5. From here, it's the same as b)
f) same as e)
g) Again we find the slope as
so the slope is -3, and a perpendicular line has slope 1/3. From there, it's the same as b).
The expected value is just the weighted average of how much one ticket wins. To calculate it, we need to find the probabilities of winning each dollar amount, multiply each probability with it's respective dollar amount, then find the sum.
Let's call the winnings from one ticket X:
P(X=30) = 4000/2000000 = 0.002
P(X=800) = 500/2000000 = 0.00025
P(X=1200000) = 1/2000000 = 0.0000005
E(X) = 30*P(X=30) + 800*P(X=800) + 1200000*P(X=1200000) = 0.06 + 0.2 + 0.6 = 0.86
The answer is $0.86
It is b, I’m a teacher and I have taught my students that.
The answer you are looking for is 0.14285714285
Answer:
C. 7.9 + x
Step-by-step explanation:
Given - A. 7.9x B. 7.9 · (-10) C. 7.9 + x D. - 79
To find - Which expression doesn't belong? Why does it not belong?
Proof -
As given
A. 7.9x
B. 7.9·(-10)
C. 7.9 + x
D. -79
As we can see that Option A, B, D are the multiple of 7.9 but Option C is not the multiple of 7.9
So, Option C does not belong here.
∴ we get
The correct answer is - C. 7.9 + x
