[" 1.Find the angles between the following pairs of straight lines "y=(2-sqrt(3))(x+5)" and "y=(2+sqrt(3))(x-7)],[" ( Find the tangent of the angle between the lines whose intercepts on the axes are "(a,-b)" and "(b,-a)" ."],[" Find the equation of the straight line which is parallel to the line "4x-5y+3=0" and nassect the "],[" point "(2,3)" ."]