Exercise 1 Page 145

Every equation has an $\text{equal}$ $\text{sign}$ and values or expressions on either side of it. Key phrases such as $\text{is},$ $\text{is}$ $\text{equal}$ $\text{to},$ and $\text{equals}$ tell us about the placement of the equal sign. On the left-hand side, we have two keywords: sum and times. These words tell us the operations that will be used in our equation. Sum indicates addition, while times indicates multiplication.

$$\begin{array}{c}\text{the sum of }\text{six}\text{ and}\text{ four times }d\\ 6+4d\end{array}$$

On the right-hand side, the keyword is minus. It tells us to subtract.

$$\begin{array}{c}d\text{ minus }\text{nine}\\ d-9\end{array}$$

Putting these sides together, we have a complete equation.

$$\begin{array}{c}6+4d=d-9\end{array}$$