Line ef has an equation of a line y = −2x + 7. which of the following could be an equation for a line that is perpendicular to line ef?

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