Chau currently has \( \$ 42 \) in savings. He had been saving \( \$ 7 \) each week. Yesterday he spent \( \$ 77 \) of the savings. For how many weeks had he been saving? (a) Write an equation that could be used to answer the question above. First, choose the appropriate form. Then, fill in the blanks with the numbers 42,7 , and 77 . Let \( w \) represent the number of weeks. \( \square w+\square=\square \) \( \square w-\square=\square \) (b) Solve the equation in part (a) to find the number of weeks. w \( =\square \)

To find the number of weeks Chau had been saving, we can analyze the situation step by step. First, since Chau had \( \$ 42 \) in savings and spent \( \$ 77 \), the savings before spending would be: Initial savings = spending + current savings = \( 77 + 42 = 119 \). Now, if he saves \( \$ 7 \) each week for \( w \) weeks, we can say: \( 7w = 119 \). Thus, the equation becomes: \( 7w + 0 = 119 \). Now, let's solve for \( w \): (a) The equation can be filled in as follows: \( 7w + 0 = 119 \) (b) To solve for \( w \): \[ 7w = 119 \\ w = \frac{119}{7} \\ w = 17 \] So, Chau had been saving for \( w = 17 \) weeks.