Answer:
Step-by-step explanation:
Incomplete question.
Answer:
Cost of one pencil: 
Cost of one eraser: 
Step-by-step explanation:
Let be "p" the cost in dollars of one pencil and "e" the cost in dollars of one eraser.
Based on the information given in the exercise, you can set up the following system of equations:

You can use the Elimination Method to solve the system of equations.
Multiply the first equation by -3 ad the second one by 4. Then add the equations and solve for "e":
{
Substitute the value of "e" into any original equation and solve for "p":

Question has missing details (Full question below)
Measurement error that is continuous and uniformly distributed from –3 to +3 millivolts is added to a circuit’s true voltage. Then the measurement is rounded to the nearest millivolt so that it becomes discrete. Suppose that the true voltage is 219 millivolts. What is the mean and variance of the measured voltage
Answer:
Mean = 219
Variance = 4
Step-by-step explanation:
Given
Let X be a random variable measurement error.
X has a discrete uniform distribution as follows
a = 219 - 3 = 216
b = 219 + 3 = 222
Mean or Expected value is calculated as follows;
E(x) = ½(216+222)
E(x) = ½ * 438
E(x) = 219
Variance is calculated as follows;
Var(x) = ((b-a+1)²-1)/12
Var(x) = ((222-216+1)²-1)/12
Var(x) = (7²-1)/12
Var(x) = 48/12
Var(x) = 4
1470 because 0.52 is close to the whole
Answer:
-5n²-8n+4
Step-by-step explanation:
Remove Parentheses :
3n²-5n+6 - 8n²-3n-2
Collect/Combine Like terms:
(3n²-8n²) + (-5n-3n) +(6-2)
Simplify:
-5n²-8n+4