Mia’s work to find the slope of a trend line through the points (3, 10) and (35, 91) is shown below.

Mia’s Work

Step 1

StartFraction 3 minus 35 Over 10 minus 91 EndFraction

Step 2

StartFraction negative 32 Over negative 81 EndFraction

Step 3

StartFraction 32 Over 81 EndFraction

What was the first error that Mia made?

Mia simplified incorrectly and made the slope positive.

Mia subtracted in the wrong order.

Mia switched the numerator and the denominator.

Mia used subtraction instead of addition.