What property is being shown?

5+(6+3) = (5+6) +3

Solve by any method (graphing, substitution or linear combination)y = x - 82x + 3y = 1a) (2, -6)b) (5, -3)c) (4, -4)d) (0, -8)i figured it out. the answer is (5, -3)

Measures of the angle of r, 31 s (x+4) t (3x+9)

2pointswhich of the following appear in the diagram below? check all that apply.d a. zcdeов. сеo c. aéo d. zdce