2 because the equation can be reduced to: 8.0 x 10^4.
We have this equation for the slope is: y=mx+b which m is the slope and b is the y-intercept, so we have y=20-15x or y=-15x+20, and we already know that the slope is -15 and y-intercept is 20. As a result, the student's error is that he thinks that 20 is the slope because it is the first number. Hope it help!
Answer:

Step-by-step explanation:
The sides AB and CD are parallel to the x-axis and 5 units apart. The length of side AB is 6-(-12) = 18 units. The area is the product of these dimensions:
Area = (Base)(Height) = (18 units)(5 units) = 90 units²