Answer
A) $.3$
B) The cost to rent a newly released movie increases value by $30$ cents for every year since $2010$.
C) The cost to rent a newly released movie in $2010$ is $5$ dollars.
Work Step by Step
A) In the function $f(x)=ax+b$, the slope is defined by the $a$ value, which in this example is $.3$.
B) The rate of change in this function can be represented by $(.3(x+1)+5)-(.3(x)+5)$. Solve this expression by doing $(.3x+.3+5)-(.3x+5)=.3$ This is the amount that is added to the cost for every year since $2010$. Rewrite this as "the cost to rent a newly released movie increases value by $30$ cents for every year since $2010$".
C) If $f(x)=.3x+5$, then $f(0)=.3(0)+5=0+5=5$. To translate this, $0$ years since $2010$ is $2010$, and the cost to rent a newly released movie is $5$ dollars. Rewrite this as "the cost to rent a newly released movie in $2010$ is $5$ dollars".