Which is equal to a rotation of 90°ccw? A. 180°cw rotation about the origin
В. 270°cw rotation about the origin
C. 180ºccw rotation about the origin
D. 270ºccw rotation about the origin

В. 270°cw rotation about the origin

Step-by-step explanation:

We can rotate a total of 360 degrees in a circular pattern.

If we rotate x degrees in one direction, this rotation is equivalent to rotating (360 - x) in the other direction, because we would arrive in the same place.

So if we rotate 90 degrees in the counter clockwise direction, this is equivalent to rotating (360 - 90) = 270 degrees in the opposite direction, that is, in the clockwise direction.

So the correct option is B. -> 270°cw rotation about the origin.

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