First of all, we need to find the slope of the given line, writing it in the form and reading the
coefficient:
So, the slope is
If a line with slope is perpendicular to a line with slope
, the following relationship holds:
So, the slope of our line must satisfy
So, we need the equation of a line with slope 1 and passing through (4,7). Given the slope and a point
of a given line, its equation is given by
So, if you plug your values, you have