A.2.2—Changing the subject of an equation

Changing the subject means isolating one variable while applying the same inverse operation to both sides. Keep brackets and units visible until the rearrangement is complete.

Undo addition before multiplication, undo powers with roots and check the final form by substituting a simple value into both the original and rearranged equations.

From rate = distance/time, multiply by time to obtain distance = rate × time; the units become distance per time × time = distance.

Rearranging is not the same as changing a sign or moving a term without applying an operation to both sides.