APPENDIX B - Coordinate Geometry and Lines - B Exercises - Page A 15: 21

$y=6x-15$

To find an equation of a line with slope $m=6$ that passes through $(2,-3)$, we use the formula $y=mx+b$. We plug in the values of $m$, $y$, and $x$ to solve for $b$: $-3=6(2)+b$. Solve for $b$: $b=-15$. Plug values of $m$ and $b$ into equation to get the equation of line: $y=6x-15$.