Question

9.

A. She used y-values where she should have used x-values.

B. She did not keep the order of the points the same in the numerator and the denominator.

C. She mixed up the x- and y-values.

D. She should have added the values, not subtracted them.

Answer 1

B. She did not keep the order of the points the same in the numerator and the denominator.

Explanation:

The formula to calculate slope is:

`(y_(1)-y_(2))/(x_(1)-x_(2))`

She instead used this formula:

`(y_(1)-y_(2))/(x_(2)-x_(1))`

The student made the mistake of not keeping the numerators and denominators in the same order.