Answer
$\$41.69$.
Work Step by Step
Cell phone plan cost $C=\$39.99$ per month.
For every text message $x=\$0.10$.
Total messages received and sent $=7+10=17$.
Total cost $=17\times 0.10 =\$1.7$.
The bill for this month
$=\$39.99+\$1.7$
$=\$41.69$.
