Answer:
An expression to represent the number of butterflies he has is y = 12 + 2x
Step-by-step explanation:
Let the number of butterflies in Eduardo’s collection be y
Then according to the question
The number of moths = x
The number of butterflies y = 12 + twice the number of moths---------(1)
Twice the number of moths = 
Twice the number of moths = 2x -----------------------(2)
Substituting equation (2) in (1)
The number of butterflies y = 12 + 2x
I think the answer is 1.06666666667
To determine the probability that the car from Sanger's auto garage needs an oil change and also tire rotation, we multiply the probability of the first event and the second event. We get an equation of,
= (3/5) x (4/7) = 12/35
Thus, the probability that the car needs both oil change and tire rotation is 12/35.
A)

B)

We first find the z-score associated with the level of confidence. For 95% confidence:
Convert 95% to a decimal: 0.95
Subtract from 1: 1-0.95 = 0.05
Divide by 2 (this is the area in the tails): 0.05/2 = 0.025
Subtract from 1 (we don't want the tails, we want the area in the middle): 1-0.025 = 0.975
Using a z-table (http://www.z-table.com) we find the z-score for this is 1.96. We now use the formula

For a 98% confidence level:
Convert 98% to a decimal: 0.98
Subtract from 1: 1 - 0.98 = 0.02
Divide by 2: 0.02/2 = 0.01
Subtract from 1: 1 - 0.01 = 0.99
Using the z-table we see the closest number to this is for the z-score 2.33:
The answer is B because the bottom has to be supplementary to 180 degrees because their supplementary angles