What do you know about the slope when y2 - y1 = 0 ?
a. the slope is undefined.
b. the slope is zero.
c. the slope is positive.
d. the slope is negative.

B

Step-by-step explanation:

Using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

If y₂ - y₁ = 0 then slope is zero

This applies to a horizontal line parallel to the x- axis

how is that middle school

step-by-step explanation:

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong