We are given with two coordinates (10, 7, 20) and (5, 3, -2) Which can be used to create a linear equation represented by vectors <x, y, z> = <x0, y0, z0> + t<mx, my, mz> We can get the slope by <mx, my, mz> = <10, 7, 20> - <5, 3, -2> = <5, 4, 22>
<x, y, z> = <x0, y0, z0> + t<5, 4, 22> At z = 0, and using the coordinates of either of the two points, the coordinates o the shadow of the point can be determined.
When adding negative with positive it will always be negative so for this question, subtract -28 with 15 which would be -43. So -43 would be the temperature in the evening.
