F(x) = x^2 - 3x - 7
f(-3) = (-3)^ 2 - 3(-3) - 7
f(-3) = 9 + 9 - 7
f(-3) = 18 - 7
f(-3) = 11
Answer:
Let x and y be the two positive integers the Christopher is thinking.
x is equal to 7
and y =20
We can plot this data on MS Excel and determine the distribution of these data reflected on the graph. Among these numbers, 50 is the outlier since it is very far from the other numbers ranging from 76 to 83. We can perform interquartile range to determine or verify the outliers in the data set. In this respect, we can see that there is not much distribution seen. The average of all data sets is equal to 96.25. When the outlier (50) is removed, we expect the mean to become higher since a low number was ommitted including high numbers only. Outliers are obtained from special causations such as human errors.
Let x and y be the rate per hour for Mechanic 1 and 2 respectively.
Then,
x+y=205 ---------- (1)
Additionally,
10x+15y = 2500 ------ (2)
Solving equations 1 and 2;
Multiply (1) by 10 and subtract two from the result,
10x+10y = 2050
10x +15 y =2500
----------------------
-5 y = --450 => y = 450/5 = $90
Then,
x= 205-90 = $115
Therefore,
Mechanic 1 charged $115 per hour
Mechanic 2 charged $90 per hour