How do you write an equation for a circle tangent to the line 5x + y = 3 at the point (2,-7) and the center is on the line x – 2y= 19?
Please see the explanation. The equation is:
Write the equation of the tangent line in slope-intercept form so that we may observe its slope.
Because radius of the circle at point (2, -7) will be perpendicular to the tangent line, the slope of the radius is the negative reciprocal of the slope of the tangent line,
Substitute equation  into equation :
Substituting for x in equation :
Substitute the center
#r = sqrt(26)