A garden is 3m wThere is a pathway that runs along the perimeter inside the garden.If the area of pathway is half of the area of garden, then the width of the pathway is how many meters?

3m wide, but how long?

Anyway, if it is x meters long, then you need

3x - (3-2w)(x-2w) = 3x/2

because the area of the whole thing minus the area inside the pathway is the area of the pathway.

So, plug in your length for x, and then solve for w.