How to solve multi-step equations

To solve an equation like this, you must first get the variables on the same side of the equal sign. Add -2.5y to both sides so that the variable remains on one side only. Now isolate the variable by subtracting 10.5 from both sides. Multiply both sides by 10 so that 0.5y becomes 5y, then divide by 5.

You have 2 sides that are 2 cms and you have 6 sides that are 1/2 cm and you have 4 sides that are 1 cm. the smallest sides are 1/2 the medium sized sides are 1 and the smallest are 1/2. so to find the perimeter you have to add them all up together so your answer will be 11 cm's