Answer:
The equation for the number of dollars, d, you spend on b boxes is:
  d=6b
Explanation:
You buy boxes of strawberries at the market. 
Each box cost $6. 
Write an equation for the number of dollars, d, you spend on b boxes.
Cost of 1 box=$6
Cost of b boxes=$6b
Dollars spent=d=6b
Hence, the equation for the number of dollars, d, you spend on b boxes is:
 d=6b