The perimeter of a triangle is 7X minus 3Y +6 feet the length of two sides of the triangle are 2X +y -1 feet and X minus 2Y +10 feet find the length of the third side in terms of X and y

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.