Split it into 7 triangles. Half-base of each is 2 so the distance of center to the midpoint of the base is (Pythagoras) square root of (4.62 - 22) = 4.162 triangle is this times 2, and with 7 triangles multiply also by 7 to get an approximate area of 58 sq in.
She is correct because a negative subtracted by a negative is positive.
The 0.25 is the rate of change per each time. the 10 is what it started it
I think it’s 1384939384$3
The independent variable is is the price per bag.