Katie and Pamela put some money into their money boxes every week. The amounts of money (y), in dollars, in their money boxes after certain amounts of time (x), in weeks, are shown by the equations below:
Katie y = 30x + 20
Pamela y = 20x + 90
After how many weeks will Katie and Pamela have the same amount of money in their money boxes, and what will that amount be?
6 weeks, $150
6 weeks, $230
7 weeks, $150
7 weeks, $230