In a different plan for area codes, the first digit could be any number from 1 through 7, the second digit was either 4, 5, 6, or 7, and the third digit could be any number except 2. With this plan, how many different area codes are possible?

astronomers is your final answer! : )

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

a

step-by-step explanation: