The total cost when 881 minutes is used is $477.50.
a + 480b = 277 equation 1
a + 990b = 532 equation 2
Where:
Subtract equation 1 from equation 2
510b = 255
b = 255 / 510
b = $0.50
In order to determine the flat fee, substitute for b in equation 1
a + 480(0.5) = 277
a + 240 = 277
a = 277 - 240
a = $37
Total cost = flat fee + (variable cost x number of minutes spoken)
$37 + (881 x 0.5) = $477.50
To learn more about simultaneous equations, please check: https://brainly.com/question/25875552
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