A.2.4—Solving algebraic equations

An equation remains true when the same operation is applied to both sides. Isolate the unknown, preserve brackets and check the solution in the original expression.

Undo addition or subtraction, then multiplication or division; for powers use the appropriate root. Keep units attached to quantities when the equation represents a biological measurement.

If 3x + 2 = 11, subtract 2 then divide by 3 to obtain x = 3; substituting 3 restores 11.

Squaring or taking roots can introduce or remove solutions, so verify every candidate.