What is the slope of a line that is perpendicular to the line y = 1?

Undefined ( ∞ )

Step-by-step explanation:

The given line is y=1

It is horizontal line on coordinate plane.

Because y=k means y become constant and x varies.

If we draw perpendicular to horizontal line then it would be vertical line.

The equation of vertical line, x=h

The slope of horizontal line is 0

The slope of vertical line is undefined.

Because vertical line makes angle with x-axis 90°

Slope = tan 90°

∵ tan 90° is undefined.

Hence, The slope of perpendicular line of y=1 is undefined.

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.