The coefficient of


x is

7
8

8
7

, which means that as

x increases, the term

7
8


8
7

x becomes more negative. Since the left side of the equation is equal to the right side, the overall result must be
21
21 minus some negative value. rephrase as a 8th grader

The number in front of x is -7/8, which means that as x gets bigger, the number becomes more negative. Since the left side of the equation equals the right side, the final answer is 21 minus a negative number.