C. For each hour he works, his earnings go up by $8.
Try this solution:
let the unknown two-digits number be 'xy'.
Then it is possible to write any two-digit number as 10x+y, where x - the tens digit and y - the unit digit.
Using the rule described above the phrase 'the tens digit of a number is twice the units digit' may be written as x=2y.
Using the same rule the phrase 'if the digits are reversed, the new number is 36 is less than the original number' may be written as (10x+y)-(10y+x)=36.
These two equations may be resolved as system of two equations:

Check: the original number is 84, the new number is 48; difference is 84-48=36.
answer: 84
Answer:
D
Step-by-step explanation:
If you look at the right side of each piecewise function, you will see the x-values. That is what we will be focusing on in this explanation. All four equations have x <u>></u> 4, and we know that to be true. If you look at the equation on the graph going South West, you will see that the endpoint is at x=1. Only 1 equation, D, has this in the piecewise function. To confirm it is D, you can see that 1<x<4 is also in the piecewise function, and all the values line up with their corresponding y-values.
Hope this helps! :)
Answer:
1. k=1, b=1
2. k=-1, b=-0.5
Step-by-step explanation: