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)
-9 x 1/3
= -9/3
= -3
......................................
The answer to 84 divided by 4=21.
See examples before for the method to solving literal equations for a given variable: Solve A = bh for b. Since h is multiplied times b, you must divide both sides by h in order to isolate b. Since (c+d) is divided by 2, you must first multiply both sides of the equation by 2.