Answer:
[tex]c\leq \$17[/tex]
Step-by-step explanation:
Let
c -----> the additional amount (in dollars) David will spend
we know that
The word " at most" in this context means "less than or equal to"
The amount David has spent plus possible additional amounts he will spend must be less than or equal to $39
so
The inequality that represent this situation is
[tex]22+c\leq 39[/tex]
solve for c
subtract 22 both sides
[tex]c\leq 39-22[/tex]
[tex]c\leq \$17[/tex]
The maximum amount he could spend is $17