Solution: The straight line L passes through point A(x0, y0). According to the point inclination equation of the straight line, let the equation of the straight line L be y-y0=k(x-x0). Because it is perpendicular to the straight line Ax+By+c=0, the product of the slopes of the two straight lines is-1, that is, k *(a/b)= 1

Hope to adopt,

The handwriting was ugly, so I typed it out for fear that you wouldn't recognize me and adopt me.