write an equation in point-slope form for the line through the given point with the given slope. point 4, negative 6; m equals three fifths. a. y plus 6 equals 3 fifths x minus 4 end. b. y minus 6 equals 3 fifths times the quantity x plus 4 end of quantity. c. y plus 6 equals 3 fifths times the quantity x minus 4 end of quantity. d. y minus 4 equals three fifths times the quantity x plus 6 end of quantity.