The linear function graphed below represents the value of a comic book since Lucy purchased it. What was the value of the comic book when Lucy bought it?
Accepted Solution
A:
Answer:C. $25Step-by-step explanation:We will find,The slope of the function using [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}[/tex].Taking the points (1,40) and (2,55).Slope = [tex]\frac{55-40}{2-1}[/tex]i.e. Slope = [tex]\frac{15}{1}[/tex]i.e. Slope = 15Substituting the slope and point (1,40) in the equation [tex]y=mx+b[/tex],We have, [tex]40=15\times 1+b[/tex]i.e. [tex]b=40-15[/tex]i.e. b= 25Thus, the equation of the linear function is [tex]y=15x+25[/tex].This linear function represents the cost of the comic book since Lucy purchased it, where x= years.So, the initial value of the comic book is when x= 0.So, [tex]y=15\times 0+25[/tex] i.e. y= 25Hence, the cost of the book when Lucy purchased it was $25.