When the width of a rectangle is 3 more than twice the length and the perimeter is 60 find the length and the width?

You can write equations for each of the two facts provided, then solve the equations. If you call the length "l", and the width "w", the facts are:3 more than...: w = 2l+3

perimeter: 2(l+w)=60

This is fairly easy to solve if you replace the first equation in the second (in the second equation, replace "w" by the expression that is on the right, in the first equation).