Which angle(s) is/are congruent? There may be more than one answer

Give the equations of two different lines that are perpendicular to the line 3x + 4y = 7.

Find two numbers if their sum is 91 and the ratio is 6: 7?

Whoever gets this right gets the ! the half life of a soul smelling substance is 4 years. if you have 8 oz of this strange substance, how much of it will you have after 20 years? show work.