Y is inversely proportional to a^3 whe a=2 y=10 a is directly proportional to x whenx=4 a=20 find a formula

Which two properties of equality could zoe use to finish solving for x? the equation is 3x - 4 = -10 for x so a either the addition or subtraction property of equalityb ether the multiplication or division property of equality c ether the addition or division property of equality d ether the subtraction or division property of equality just a simple a b c or d plz.