If (r, s) is the solution to the system of equations, what is the value of r?

−8r − 8s = 100 r − 2s = 10

A) −5
B) − 15/2
C) 5
D) 15/2

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.