hi guys!! i really need help in my assignment...can you help me solve this?:

a.) What are the equations of the lines through (-5,-3) and passing at distance two square root of five from (5,7)?

b.)A point moves so that the ratio of its distances from 3x+4y+8=0 and 4x+3y-6=0 is 2. find the equation of its locus.

I really need to answer this today.. please help me...