PorfaaaáaaaEs urgente?

Solución :

<img src="https://tex.z-dn.net/?f=%5Ctextup%7BPuesto%20que%20el%20per%5C%27imetro%20es%20la%20suma%20de%20los%20lados%7D%5C%5C%5Ctextup%7Bdel%20pol%5C%27igono%20y%20en%20este%20caso%20%0Avale%7D%5C%5C%2028x%5E%7B3%7Dy%5E%7B2%7D%5C%2C%5Ctextup%7Bentonces%20restando%20al%20per%5C%27imetro%7D%5C%5C%5Ctextup%7Bla%20suma%20de%20los%20otros%20lados%20obtendremos%7D%5C%5C%5Ctextup%7Bel%20lado%20faltante%2Cpor%20lo%20tanto%3A%7D%5C%5CP%3D28x%5E%7B3%7Dy%5E%7B2%7D%5C%5C28x%5E%7B3%7Dy%5E%7B2%7D-%284x%5E%7B3%7Dy%5E%7B2%7D%2B10x%5E%7B3%7Dy%5E%7B2%7D%2B3x%5E%7B3%7Dy%5E%7B2%7D%2B2x%5E%7B3%7Dy%5E%7B2%7D%29%3D%5C%5C28x%5E%7B3%7Dy%5E%7B2%7D-%2819x%5E%7B3%7Dy%5E%7B2%7D%29%3D28x%5E%7B3%7Dy%5E%7B2%7D-19x%5E%7B3%7Dy%5E%7B2%7D%3D%5C%5C9x%5E%7B3%7Dy%5E%7B2%7D%5C%5C%5Ctextup%7BAs%5C%27i%20el%20lado%20faltante%20mide%3A%7D%5C%5C9x%5E%7B3%7Dy%5E%7B2%7D" />

Saludos.