Refrection of (-20, 4) across x-axis gives (-20, 4) = (-20, -4)
Refrection of (-20, 4) across y-axis gives (20, 4)
Refrection of (-20, 4) across y = -x gives (20, -4)
Refrection of (-20, 4) across y = 7 gives (20, 10)
(-X-13)+(X+13)+(X-13)
The positive x and negative x cancel out and equal zero. The positive 13 and negative 13 cancel and equal zero also. Then you are left with (x-13)
Yes because it create lines that won’t hit two points (probably doesn’t make sense)
Yes
Reason
Each simplified is 2:5
Let's check if the ODE is exact. To do that, we want to show that if

then

. We have


so the equation is indeed exact. We're looking for a solution of the form

. Computing the total differential yields the original ODE,


Integrate both sides of the first PDE with respect to

; then

where

is a function of

alone. Differentiate this with respect to

so that



So the solution to this ODE is

i.e.