## Geometry: Common Core (15th Edition)

I) $y=5x-8$
A line can be defined by the formula $y=mx+b$, where m is the slope of the line and b is the y-intercept. If two lines are parallel, then by definition they have the same slope. Substitute the given values for the parallel line into the slope-intercept formula to find the y-intercept. We know the slope is 5, and we have been given a pair of points that are on the line. $y=mx+b$ Substitute. $-3=5(1)+b$ Subtract 5 from each side. $-3-5=5+b-5$ Simplify. $-8=b$ So the slope of the parallel line is 5 and the y-intercept is -8. Substitute these values into the slope-intercept formula to create an equation for the line. $y=mx+b=5x-8$