Х/y = h-k solve for y

Given δjkl : δxyz, find x. a)10 b)12 c)16 d)20

Sole the equation 6n + 9 = -3n - 21 - 6 for n

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.