Question 1208892
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x = number of kilowatt-hours
0.0944x = cost in dollars of using that amount of electricity
0.0944x+12.55 = add on the fixed fee of $12.55


The cost is somewhere between $76.27 and $248.55
I'll assume that each endpoint is included.
{{{76.27<=cost <= 248.55}}}


{{{76.27<=0.0944x+12.55 <= 248.55}}}


{{{76.27-12.55<=0.0944x+12.55-12.55 <= 248.55-12.55}}} Subtract 12.55 from all sides.


{{{63.72<=0.0944x <= 236}}}


{{{63.72/0.0944<=0.0944x/0.0944 <= 236/0.0944}}} Divide all sides by 0.0944


{{{675<=x <= 2500}}}


The usage of kilowatt-hours is somewhere between 675 and 2500.
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