Exercise 1 Page 145

Every equation has an equal sign and values or expressions on either side of it. Key phrases such as is, is equal to, and equals tell us about the placement of the equal sign. The sum of six and four timesd = dminus nine 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.

the sum of six and four timesd 6 + 4d On the right-hand side, the keyword is minus. It tells us to subtract. d minus nine d - 9 Putting these sides together, we have a complete equation. 6 + 4d = d - 9