Answer:
 (b)  35.5w + 136.45 = 455.95; w = 9
Step-by-step explanation:
You want an equation to determine how many weeks, w, you must babysit to earn $455.95 at the rate of $35.50 each week, having already saved $136.45.
If you earn $35.50 each week for w weeks, your total earnings will be ...
 35.50w
When that amount is added to the amount you already have, $136.45, the sum is ...
 35.5w +136.45
You want that total to be $455.95, which gives you the equation ...
 35.5w +136.45 = 455.95
To solve this 2-step equation, subtract the left-side constant:
 35.5w = 319.50
The second step is to divide by the coefficient of the variable:
 w = 319.50/35.5
 w = 9
