Answer:
The bill is $30
Step-by-step explanation:
Given
[tex]b(x) = \left \{ {{0.10x,\ x \le 200} \atop {0.15(x - 200)\ x > 200}} \right.[/tex]
See attachment
Required
Determine the bill when KWh = 400
From the given piece-wise function.
We make use of:
[tex]b(x) = 0.15(x - 200)[/tex]
Because [tex]400 > 200[/tex]
Substitute 400 for x in b(x)
[tex]b(400) = 0.15 * (400 - 200)[/tex]
[tex]b(400) = 0.15 * 200\\[/tex]
[tex]b(400) = 30[/tex]
The bill is $30