How many different combinations of “on” and “off” are possible with 8 “lightbulbs”?

How many different combinations of “on” and “off” are possible with 8 “light bulbs”?

The total number of combinations of "on" and "off" that are possible with 8 "light bulbs" is

Therefore, 256 different combinations of “on” and “off” are possible with 8 “light bulbs”

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