Write an equation in slope-intercept form of the line that passes through the points (7, - 4) and (3, -1). y =
x+
please help ASAP

Isabelle is mixing red and blue paint to make purple paint she adds 3/10 of a fluid ounce of red to 12/25 of a fluid ounce of blue to make 1 1/30 fluid ounces of purple how many fluid ounces of red paint ounces of red paint will she need to make 3 fluid ounces of purple paint