Are the graphs of the lines in the pair parallel? explain. y = 6x + 9 27x – 3y = –81

For the 2nd equation, you need solve for y to get it by itself so once thats done you get y=9x+27 but since the x values (also the slope) aren't equal, they can't be parallel

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.