Question

13a. Jose decides to bike 165 miles and figures he can maintain aspeed of 15 mi/hr. Which of the linear equations below representsthe number of miles (y) Jose will have LEFT to reach his goal after acertain number of hours (x)?A y=-15x + 165B y=-15x-165C y = 15x-165D y = 15x+165E y = 15x + 165

Answer 1

Solution:

Given that Jose decides to bike 165 miles and figures he can maintain a speed of 15 mi/hr, this implies that

$\begin{gathered} total\text{ distance travel = 15x + distance left} \\ where \\ x\Rightarrow time\text{ spent in maintaining the speed} \end{gathered}$

Thus, we have

$\begin{gathered} 165=15x+y \\ add\text{ -15x to both sides of the equation,} \\ -15x+165=-15x+15x+y \\ \Rightarrow y=-15x+165 \end{gathered}$

Hence, the number of miles left to reach his goal is expressed as

$y=-15x+165$

The correct option is A