Question

Use slopes and y-intercepts to determine if the lines −4x+4y=−1 and 4x+4y=−1 are parallel.

Answer 1

Nope they are not parallel.

Explanation:

first find the slope of each equation.

-4x+4y= -1

4y= 4x -1

y= (4x-1)/4

y=x - 1/4

the other equation

4x +4y = -1

4y= -4x -1

y= (-4x-1)/4

y= -x -1/4

the slope is the number in front of the x so for the first equation, it is 1 and the second equation it is -1. Since they are not the same, they are not parallel but instead is perpendicular. TBH, just stop here as this is more than enough.