Answer: 264.33 + 0.05m = 291.33
Step-by-step explanation:
$26.70 a month for 800 minutes (multiply this by 9 as seen in the equation below since the bill is for 9 months)
$0.05 per additional minute (we don't know how many additional minutes were used so put an m as seen in the equation below)
email is 10% of $26.70 = $2.67 (multiply this by 9 as seen in the equation since the bill is for 9 months)
total bill is $291.33 for 9 months
put the values into an equation.
26.70(9) + 2.67(9) + 0.05m = 291.33
240.30 + 24.03 + 0.05m = 291.33
264.33 + 0.05m = 291.33
0.05m = 27
m = 540 total additional minutes