Flying against the wind, a plane traveled 3,960 kilometers in 6 hours. With no change in the wind speed or direction and with the same engine speed, the return trip took 5.5 hours.

Step-by-step explanation:

I have the same question, is this trig, pre-cal or algebra?

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