#### Answer

3(7-d)

#### Work Step by Step

We see that there is "the difference of," 7 and d, so we know that we should subtract 7 and d. Because 7 is listed first, we know that it should also be listed first in the subtraction. The phrase also says that the algebraic expression should be 3 times the difference of 7 and d, so we know after we find the difference, we should multiply by 3. We add parenthesis to show that we subtract before we multiply. Thus, we find: 3(7-d)