Ataxi charges $7.50 plus $0.45 per mile.

alexis rode 16 miles to work.

she walked half way home.

how much does she pay for the taxi ride per day?

$7.50(2)=$15.00 (She takes the taxi twice, and its $7.50 each time she takes it)
$0.45(16)+$0.45(8)=$10.80 (Each mile is $0.45, she goes 16 miles on the way to work, and only 8 miles on the way home. Since she walks half way and  takes the taxi the other half. Half of 16 is 8)
$15.00+$10.80=$25.80
Alexis pays $25.00 per day for her taxi rides.