Exercise 30 Page 16

Every equation has an $\text{equals}$ $\text{sign}$ and values or expressions on either side of it. Key phrases, such as $\text{is},$ $\text{is equal to},$ and $\text{equals}$ tell us about the placement of the equals sign. On the left-hand side, we have two key words: difference and times. These words tell us the operations that will be used in our equation. Difference indicates subtraction, while times indicates multiplication. The phrase a number indicates a variable, which we will call $n.$ On the right-hand side, we only have $\text{-}19.$ Putting these sides together, we have a complete equation. Finally, we can solve the equation we have written. We will do this using inverse operations and following the Properties of Equality.