Compare and contrast expanding and simplifying algebraic expressions with simplifying numeric expressions. For example, compare simplifying 3(x – 2) + (x – 1) with 3(5 – 2) + (5 – 1).

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

think the answer is 30 degrees. if not than it is 20 degrees. not 100% sure. let me know if it was right.

gill russ

by definition every angles supplementary opposite by vertex are congruent