substitute
sustituir
to replace each letter in a formula with its number value so you can calculate the answer.
Example
To use d = \dfrac{m}{V} with m = 54 g and V = 20 mL, substitute to get d = \dfrac{54}{20} = 2.7 g/mL.
In Spanish
sustituir — reemplazar cada letra de una fórmula por su valor numérico para poder calcular la respuesta.
Para usar d = \dfrac{m}{V} con m = 54 g y V = 20 mL, sustituye y obtienes d = \dfrac{54}{20} = 2.7 g/mL.