This would be a positive answer because 400/2 = 200 which is a positive number/integer
To find slope you need to use the coordinates of two points on the line. If the coordinates are (x1, y1) and (x2, y2) do y2-y1 / x2-x1 to find the slope.
So far in the equation of a line, y=mx+b, you have the "m" which is the slope.
Plug in the slope, and the x and y values from one of the points and solve for b, which is the y intercept.
Here's an example if the coordinates are (1,4) and (2,6):
6-4/2-1 = 2/1 = 2
The slope is 2.
y = 2x + b
4 = 2(1) + b
4 = 2 + b
4-2 = 2-2 + b
2= b
The full equation is y = 2x + 2
The suit case originally weights 48 kg
.75x = 36x = 33/ .75 = 48