Solving an equation means finding a value of a variable that make the equation true. This value is called the solution of the equation. A mathematical equation is just like a balanced equation. Both sides of the equation should be equal at all times. Whatever we do to one side, has to be done on the opposite side.
[tex]A=2(l+w) [/tex]
[tex] \dfrac{a}{2}=l+w
[/tex] [tex]Divide \ both \ sides \ by \ 2[/tex]
[tex] \dfrac{a}{2}-l=w
[/tex] [tex]Subtract \ l \ from \ both \ sides[/tex]
[tex]w= \dfrac{a}{2}-l [/tex]
