Answer: 8 hours
Step-by-step explanation:
Given : The cost "c" (in dollars) of renting a paddle board for "h" hours is given by [tex]c=25+7h[/tex]
Now, put the value of c= 81 in the given equation, then we have
[tex]81=25+7h[/tex]
Subtract 25 on both sides , we get
[tex]7h=81-25\\\\\Rightarrow\ 7h=56[/tex]
Now, divide 7 on the both sides , we get
[tex]h=8[/tex]
Hence, the number of hours for the cost of $81 = 8
